Abies concolor (White fir)
Abronia
    maritima (Red sand-verbena)
    nana var. covillei (Coville's dwarf abronia)
    pogonantha (Mojave sand-verbena)
    turbinata (White sand-verbena)
    umbellata var. umbellata (Pink sand-verbena)
    villosa var. aurita (Chaparral sand-verbena)
    villosa var. villosa (Desert sand-verbena)
Abutilon
    abutiloides (Shrubby mallow)*
    palmeri (Palmer's mallow)
Acacia
    baileyana (Cootamundra wattle)*
    greggii, see Senegalia greggii
    longifolia (Golden wattle)*
Acalypha californica (California copperleaf)
Acamptopappus
    shockleyi (Shockley's goldenheads)
    sphaerocephalus var. hirtellus (Hairy goldenheads)
    sphaerocephalus var. sphaerocephalus (Goldenheads)
Acanthomintha
    ilicifolia (San Diego thornmint)
    obovata ssp. cordata (Heartleaf thornmint)
Acanthoscyphus
    parishii var. goodmaniae (Cushenbury oxytheca)
    parishii var. parishii (Parish's oxytheca)
Acer
    glabrum var. diffusum (Mountain maple)
    macrophyllum (Big-leaf maple)
    negundo (Box elder)
Achillea millefolium (Yarrow)
Achnatherum
    aridum. see Stipa arida
    coronatum, see Stipa coronata
    diegoense, see Stipa diegoensis
    hymenoides, see Stipa hymenoides
    occidentale var. occidentale, see Stipa occidentalis var. occidentalis
    parishii, see Stipa parishii var. parishii
    speciosum, see Stipa speciosa
Achyrachaena mollis (Blow wives)
Achyronychia cooperi (Frostmat)
Acmispon
    americanus var. americanus (Spanish clover)
    argophyllus var. adsurgens (San Clemente Island bird's-foot trefoil)
    argophyllus var. argophyllus (Silver lotus)
    argophyllus var. niveus (Santa Cruz Island bird's-foot trefoil)
    argyraeus var. argyraeus (Canyon bird's-foot trefoil)
    argyraeus var. multicaulis (Scrub lotus)
    brachycarpus (Hill lotus)
    dendroideus var. dendroideus (Island deerweed)
    dendroideus var. veatchii (San Miguel Island deerweed)
    denticulatus (River bar bird's-foot trefoil)
    glaber var. brevialatus (Short-winged deerweed)
    glaber var. glaber (Common deerweed)
    grandiflorus var. grandiflorus (Large-flowered lotus)
    haydonii (Pygmy lotus)
    heermannii var. heermannii (Heermann's lotus)
    maritimus var. brevivexillus (Short-bannered coastal lotus)
    maritimus var. maritimus (Coastal lotus)
    micranthus (Small-flowered lotus)
    nevadensis var. davidsonii (Davidson's lotus)
    nevadensis var. nevadensis (Sierra Nevada lotus)
    procumbens var. procumbens (Silky deerweed)
    rigidus (Desert rock pea)
    strigosus (Strigose lotus)
    wrangelianus (California lotus)
Acourtia microcephala (Sacapellote)
Actaea rubra (Red baneberry)
Adelinia grandis (Grand hound's tongue)
Adenophyllum
    cooperi (Cooper's dyssodia)
    porophylloides (San Felipe dyssodia)
Adenostoma
    fasciculatum var. fasciculatum (Chamise)
    fasciculatum var. obtusifolium (San Diego chamise)
    sparsifolium (Red shanks or ribbon bush)
Adiantum
    aleuticum (Five-finger fern)
    capillus-veneris (Maidenhair fern)
    jordanii (California maidenhair fern)
Adolphia californica (California adolphia)
Aegilops cylindrica (Jointed goatgrass)*
Aesculus californica (California buckeye)
Agastache urticifolia (Giant hyssop)
Agave
    americana (Century plant)*
    deserti var. deserti (Desert agave)
    deserti var. simplex (Single-rosetted desert agave)
    shawii var. shawii (Shaw's agave)
    utahensis (Utah agave)
Ageratina
    adenophora (Thoroughwort)*
    herbacea (Fragrant snakeroot)
    occidentalis (Western snakeroot)
Agropyron
    cristatum ssp. pectinatum (Desert crested wheat grass)*
    desertorum, see Agropyron cristatum ssp. pectinatum
Agoseris
    grandiflora var. grandiflora (Mountain dandelion)
    heterophylla var. heterophylla (Annual mountain dandelion)
    retrorsa (Spearleaf mountain dandelion)
Agrostis
    idahoensis (Idaho bentgrass)
    pallens (Seashore bentgrass)
    viridis, see Polypogon viridis
Ailanthus altissima (Tree of heaven)*
Aliciella
    hutchinsifolia (Desert pale gilia)
    latifolia ssp. latifolia (Broad-leaf gilia)
    leptomeria (Great Basin gilia)
    ripleyi (Ripley's aliciella)
    triodon (Sand gilia)
Alisma plantago-aquatica, see Alisma triviale
Alisma triviale (Water plantain)
Allenrolfea occidentalis (Iodine bush)
Allionia
    incarnata var. incarnata (Trailing windmills)
    incarnata var. villosa (Hairy windmills)
Allium
    amplectens (Narrow-leaved onion)
    atrorubens var. cristatum (Crested onion)
    burlewii (Burlew's onion)
    campanulatum (Sierra onion)
    fimbriatum var. fimbriatum (Fringed onion)
    haematochiton (Red-skinned onion)
    howellii var. clokeyi (Mt. Pinos onion)
    lacunosum var. davisiae (Davis's pitted onion)
    monticola (San Bernardino mountain onion)
    nevadense (Nevada onion)
    parryi (Parry's fringed onion)
    peninsulare var. peninsulare (Peninsular onion)
    praecox (Early onion)
Allophyllum
    divaricatum (Purple false-gilia)
    gilioides ssp. gilioides (Dense false-gilia)
    gilioides ssp. violaceum (Violet false-gilia)
    glutinosum (Sticky false-gilia)
    integrifolium (White false-gilia)
Almutaster pauciflorus (Alkali marsh aster)
Alnus rhombifolia (White alder)
Alopecurus aequalis var. aequalis (Shortawn foxtail)
Aloysia wrightii (Wright's beebrush)
Amaranthus
    albus (Pigweed amaranth)*
    californicus (California amaranth)
    fimbriatus (Fringed amaranth)
    torreyi (Torrey's amaranth)
Amauriopsis dissecta, see Hymenothrix dissecta
Amblyopappus pusillus (Coastweed)
Ambrosia
    acanthicarpa (Annual bur-sage)
    chamissonis (Silver beach bur)
    chenopodiifolia (Goosefoot bur-sage)
    dumosa (Burrobush)
    eriocentra (Woolly bur-sage)
    ilicifolia (Holly-leaved bur-sage)
    psilostachya (Western ragweed)
    pumila (San Diego ambrosia)
    salsola var. salsola (Cheesebush)
Amelanchier utahensis (Utah serviceberry)
Ammannia coccinea (Red ammannia)
Amorpha
    californica var. californica (California false-indigo)
    fruticosa (Western false-indigo)
Amphipappus fremontii var. fremontii (Chaffbush)
Amsinckia
    eastwoodiae (Eastwood's fiddleneck)
    intermedia (Common fiddleneck)
    retrorsa (Rigid fiddleneck)
    spectabilis var. spectabilis (Seaside fiddleneck)
    tessellata var. gloriosa (Bristly fiddleneck)
    tessellata var. tessellata (Checker fiddleneck)
Amsonia tomentosa (Woolly amsonia)
Anagallis arvensis, see Lysimachia arvensis
Andropogon glomeratus var. scabriglumis (Southwestern bushy bluestem)
Androsace septentrionalis (Pygmy-flower rockjasmine)
Anemone tuberosa (Desert windflower)
Anemopsis californica (Yerba mansa)
Angelica
    capitellata (Ranger's buttons)
    lineariloba (Soda straw)
    tomentosa (Woolly angelica)
Anisocoma acaulis (Scalebud)
Antennaria
    dimorpha (Low pussytoes)
    media (Alpine pussytoes)
    rosea ssp. confinis (Rosy pussytoes)
Anthemis
    arvensis (Corn chamomile)*
    cotula (Mayweed)*
Anthriscus caucalis (Bur-chervil)
Antirrhinum
    confertiflorum (Ghost flower)
    coulterianum (White snapdragon)
    filipes (Desert twining snapdragon)
    kelloggii (Twining snapdragon)
    mohavea (Lesser mohavea)
    multiflorum, see Antirrhinum thompsonii
    nuttallianum ssp. nuttallianum (Violet snapdragon)
    thompsonii (Rose snapdragon)
Anulocaulis annulatus (Sticky ringstem)
Aphanes occidentalis (Western lady's mantle)
Aphyllon
    californicum ssp. feudgei (California broomrape)
    cooperi (Cooper's broomrape)
    corymbosum (Flat-topped broomrape)
    franciscanum (Franciscan broomrape)
    parishii ssp. brachylobum (Short-lobed broomrape)
    parishii ssp. parishii (Parish's broomrape)
    purpureum (Naked broomrape)
    tuberosum (Chaparral broomrape)
    validum (Rock Creek broomrape)
    vallicolum (Valley broomrape)
Apiastrum angustifolium (Wild celery)
Apium graveolens (Common celery)*
Apocynum
    androsaemifolium (Spreading dogbane)
    cannabinum (Hemp dogbane)
Aptenia cordifolia (Baby sun rose)*
Aquilegia formosa (Columbine)
Arabidopsis thaliana (Mouse-ear cress)*
Arabis
    glabra, see Turritis glabra
    holboelii var. pinetorum, see Boechera pinetorum
    parishii, see Boechera parishii
    perennans, see Boechera perennans
    platysperma var. platysperma, see Boechera platysperma
    pulchra var. gracilis, see Boechera xylopoda
    pulchra var. pulchra, see Boechera pulchra
    rectissima, see Boechera rectissima
    repanda, see Boechera repanda
    shockleyi, see Boechera shockleyi
    sparsiflora var. arcuata, see Boechera arcuata
    sparsiflora var. californica. see Boechera californica
Aralia californica (California aralia)
Arbutus menziesii (Pacific madrone)
Arceuthobium campylopodum (Pine dwarf mistletoe)
Arctomecon merriamii (Bear poppy)
Arctostaphylos
    catalinae (Santa Catalina Island manzanita)
    confertiflora (Santa Rosa Island manzanita)
    gabrielensis, see Arctostaphylos glandulosa ssp. gabrielensis
    glandulosa ssp. adamsii (Adams' manzanita)
    glandulosa ssp. crassifolia (Del Mar manzanita)
    glandulosa ssp. gabrielensis (San Gabriel manzanita)
    glandulosa ssp. glandulosa (Eastwood manzanita)
    glandulosa ssp. glaucomollis, see Arctostaphylos glandulosa ssp. mollis
    glandulosa ssp. mollis (Transverse Range manzanita)
    glandulosa ssp. zacaensis, see Arctostaphylos glandulosa ssp. glandulosa
    glauca (Big-berry manzanita)
    insularis (Island manzanita)
    otayensis (Otay manzanita)
    parryana ssp. desertica (Desert manzanita)
    parryana ssp. parryana (Parry's manzanita)
    parryana ssp. tumescens (Interior manzanita)
    patula (Greenleaf manzanita)
    pringlei ssp. drupacea (Pink-bracted manzanita)
    pungens (Mexican manzanita)
    purissima (La purisima manzanita)
    rainbowensis (Rainbow manzanita)
    viridissima (McMinn's manzanita)
Arenaria
    kingii, see Eremogone kingii
    lanuginosa var. saxosa (Spreading sandwort)
    macradenia var. macradenia, see Eremogone macradenia var. macradenia
    ursina, see Eremogone ursina
Argemone
    corymbosa (Mojave prickly poppy)
    munita (Chicalote)
Argyrochosma jonesii (Jones' cloak fern)
Arida arizonica, see Leucosyris arida
Aristida
    adscensionis (Three-awn)
    purpurea var. nealleyi (Nealley three-awn)
Armeria maritima ssp. californica (California sea-pink)
Arnica
    chamissonis (Meadow arnica)
    mollis (Soft arnica)
Artemisia
    bigelovii (Flat sagebrush)
    californica (California sagebrush)
    douglasiana (Mugwort)
    dracunculus (Wild tarragon)
    ludoviciana ssp. incompta (Mountain wormwood)
    ludoviciana ssp. ludoviciana (Silver wormwood)
    nesiotica (Island sagebrush)
    nova (Black sagebrush)
    palmeri (Palmer's sagewort)
    rothrockii (Rothrock's sagebrush)
    spinescens (Budsage)
    tridentata ssp. parishii (Parish's sagebrush)
    tridentata ssp. tridentata (Basin sagebrush)
    tridentata ssp. vaseyana (Mountain sagebrush)
Arthrocnemum subterminale (Glasswort)
Arundo donax (Giant reed)*
Asclepias
    albicans (White-stemmed milkweed)
    californica (California milkweed)
    eriocarpa (Woolly-fruited milkweed)
    erosa (Desert milkweed)
    fascicularis (Narrow-leaved milkweed)
    nyctaginifolia (Mojave milkweed)
    subulata (Rush milkweed)
    vestita (Woolly milkweed)
Asparagus asparagoides (African asparagus fern)*
Asphodelus fistulosus (Onionweed)*
Aspidotis californica (California lace fern)
Aster
    alpigenus var. andersonii, see Oreostemma alpigenus var. andersonii
    ascendens, see Symphyotrichum ascendens
    bernardinus, see Symphyotrichum defoliatum
    chilensis, see Symphyotrichum chilense
    greatae, see Symphyotrichum greatae
    lanceolatus var. hesperius, see Symphyotrichum lanceolatum var. hesperium
    occidentalis var. occidentalis, see Symphyotrichum spathulatum var. spathulatum
    subulatus var. ligulatus, see Symphyotrichum subulatum var. paviflorum
Astragalus
    albens (Cushenbury milkvetch)
    allochrous var. playanus (Playa milkvetch)
    aridus (Annual desert milkvetch)
    bicristatus (Crested milkvetch)
    brauntonii (Braunton's rattleweed)
    calycosus var. calycosus (Torrey's milkvetch)
    cimae var. cimae (Cima milkvetch)
    cimae var. sufflatus (Inflated cima milkvetch)
    coccineus (Scarlet milkvetch)
    crotalariae (Salton milkvetch)
    curtipes (San Luis Obispo milkvetch)
    didymocarpus var. didymocarpus (Two-seeded milkvetch)
    didymocarpus var. dispermus (Dwarf white milkvetch)
    douglasii var. douglasii (Douglas's milkvetch)
    douglasii var. parishii (Parish's milkvetch)
    filipes (Narrowpod locoweed)
    gambelianus (Gambel's dwarf milkvetch)
    gilmanii (Gilman's milkvetch)
    layneae (Layne's locoweed)
    lentiginosus var. borreganus (Borrego milkvetch)
    lentiginosus var. fremontii (Fremont's milkvetch)
    lentiginosus var. micans (Shining milkvetch)
    lentiginosus var. semotus (White Mountains milkvetch)
    lentiginosus var. sierrae (Bear Valley milkvetch)
    lentiginosus var. variabilis (Varied milkvetch)
    leucolobus (Bear Valley woollypod)
    magdalenae var. peirsonii (Peirson's milkvetch)
    miguelensis (San Miguel milkvetch)
    minthorniae var. villosus (Minthorn's milkvetch)
    mohavensis var. mohavensis (Mojave milkvetch)
    newberryi var. newberryi (Newberry's rattleweed)
    nutans (Providence Mountains milkvetch)
    oophorus var. oophorus (Egg milkvetch)
    pachypus var. pachypus (Thickpod milkvetch)
    palmeri (Palmer's milkvetch)
    panamintensis (Panamint milkvetch)
    platytropis (Broad-keeled milkvetch)
    pomonensis (Pomona locoweed)
    preussii (Preuss's milkvetch)
    purshii var. lectulus (Pursh's milkvetch)
    purshii var. tinctus (Woollypod milkvetch)
    pycnostachyus var. lanosissimus (Ventura marsh milkvetch)
    sabulonum (Gravel milkvetch)
    serenoi var. shockleyi (Naked milkvetch)
    tidestromii (Tidestrom's milkvetch)
    tricarinatus (Triple-ribbed milkvetch)
    trichopodus var. lonchus (Coast locoweed)
    trichopodus var. phoxus (Santa Barbara milkvetch)
    whitneyi var. whitneyi (Whitney's locoweed)
Astrolepis cochisensis (Scaly cloak fern)
Athyrium filix-femina var. cyclosorum (Lady fern)
Athysanus pusillus (Dwarf athysanus)
Atrichoseris platyphylla (Gravel ghost)
Atriplex
    amnicola (Swamp saltbush)*
    argentea (Silverscale saltbush)
    canescens var. canescens (Four-wing saltbush)
    canescens var. laciniata (Caleb saltbush)
    canescens var. linearis (Slenderleaf saltbush)
    confertifolia (Shadscale saltbush)
    coulteri (Coulter's saltbush)
    covillei, see Stutzia covillei
    elegans var. fasciculata (Wheelscale saltbush)
    glauca (Waxy saltbush)*
    hymenelytra (Desert-holly)
    lentiformis (Quailbush)
    leucophylla (Beach saltbush)
    pacifica (Pacific saltbush)
    parryi (Parry's saltbush)
    phyllostegia, see Atriplex covillei
    polycarpa (Cattle spinach)
    prostrata (Arrowleaf saltbush)*
    semibaccata (Australian saltbush)*
    torreyi var. torreyi (Torrey's saltbush)
    triangularis, see Atriplex prostrata
    watsonii (Watson's saltbush)
Avena
    barbata (Slender oats)*
    fatua (Common wild oats)*
Ayenia compacta (California ayenia)
Azolla filiculoides (Pacific mosquito fern)
Baccharis
    brachyphylla (Shortleaf baccharis)
    douglasii, see Baccharis glutinosa
    emoryi, see Baccharis salicina
    glutinosa (Salt marsh baccharis)
    malibuensis (Malibu baccharis)
    pilularis ssp. consanguinea (Coyote brush)
    plummerae ssp. plummerae (Plummer's baccharis)
    salicifolia ssp. salicifolia (Mulefat)
    salicina (Willow baccharis)
    sarothroides (Broom baccharis)
    sergiloides (Desert baccharis)
    vanessae (Encinitas baccharis)
Bahia
    dissecta, see Hymenothrix dissecta
    neomexicana, see Picradeniopsis multiflora
Bahiopsis
    laciniata (San Diego County goldeneye)
    parishii (Parish's goldeneye)
    reticulata (Mojave goldeneye)
Baileya
    multiradiata (Desert marigold)
    pauciradiata (Lax flower)
    pleniradiata (Woolly marigold)
Balsamorhiza deltoidea (Deltoid balsamroot)
Barbarea orthoceras (Winter cress)
Bassia hyssopifolia (Five-hook bassia)*
Batis maritima (Saltwort)
Bebbia juncea var. aspera (Sweetbush)
Bellis perennis (English daisy)*
Berberis
    aquifolium var. repens (Creeping grape holly)
    fremontii (Fremont's barberry)
    nevinii (Nevin's barberry)
    pinnata ssp. pinnata (California barberry)
Bergerocactus emoryi (Golden-spined cereus)
Bernardia incana (Bernardia)
Berula erecta (Water parsnip)
Beta vulgaris ssp. maritima (Sea beet)*
Bidens
    laevis (Smooth beggar-ticks)
    pilosa (Common beggar-ticks)*
Bistorta bistortoides (Western bistort)
Bituminaria bituminosa (Pitch trefoil)*
Blennosperma nanum var. nanum (Yellow carpet)
Bloomeria
    clevelandii (Cleveland's muilla)
    crocea var. crocea (Golden stars)
    crocea var. montana (Mountain golden stars)
Boechera
    arcuata (Arching rock-cress)
    californica (California rock-cress)
    parishii (Parish's rock-cress)
    perennans (Perennial rock-cress)
    platysperma (Broad-seeded rock-cress)
    pulchra (Beautiful rock-cress)
    rectissima (Bristly-leaved rock-cress)
    repanda (Yosemite rock-cress)
    retrofracta X (Mountain rock-cress)
    shockleyi (Shockley's rock-cress)
    xylopoda (Slender beautiful rock-cress)
Boerhavia
    coccinea (Scarlet spiderling)
    coulteri var. palmeri (Coulter's spiderling)
    intermedia, see Boerhavia triquetra var. intermedia
    triquetra var. intermedia (Slender spiderling)
    wrightii (Wright's spiderling)
Bolboschoenus maritimus ssp. paludosus (Marsh bulrush)
Boschniakia strobilacea, see Kopsiopsis strobilacea)
Bothriochloa barbinodis (Cane beardgrass)
Botrychium crenulatum (Scalloped moonwort)
Bouteloua
    aristidoides var. aristodoides (Needle grama)
    curtipendula (Side-oats grama)
    eriopoda (Black grama)
    gracilis (Blue grama)
    trifida (Red grama)
Bowlesia incana (Bowlesia)
Boykinia
    occidentalis (Coast boykinia)
    rotundifolia (Round-leaved boykinia)
Brachypodium distachyon (Purple false-brome)*
Brandegea bigelovii (Brandegea)
Brassica
    fruticulosa (Mediterranean cabbage)*
    nigra (Black mustard)*
    rapa (Field mustard)*
    tournefortii (Saharan mustard)*
Brickellia
    arguta var. arguta, see Brickellia atractyloides var. arguta
    atractyloides var. arguta (Spearleaf brickellbush)
    californica (California brickellbush)
    desertorum (Desert brickellbush)
    frutescens (Shrubby brickellbush)
    incana (Woolly brickellbush)
    knappiana (Knapp's brickellbush)
    longifolia var. multiflora (Gum-leaved brickellbush)
    microphylla var. microphylla (Little-leaved brickellbush)
    multiflora, see Brickellia longifolia var. multiflora
    nevinii (Nevin's brickellbush)
     oblongifolia var. linifolia (Narrow-leaved brickellbush)
Brodiaea
    elegans (Harvest brodiaea)
    filifolia (Thread-leaved brodiaea)
    orcuttii (Orcutt's brodiaea)
    santarosae (Santa Rosa basalt brodiaea)   
    terrestris ssp. kernensis (Earth brodiaea)
Bromus
    berteroanus (Chilean chess)
    carinatus var. carinatus, see Bromus sitchensis var. carinatus
    carinatus var. marginatus, see Bromus sitchensis var. marginatus
    carinatus var. maritimus, see Bromus sitchensis var. maritimus
    diandrus (Ripgut brome)*
    hallii (Hall's brome)
    hordeaceus (Soft chess)*
    rubens (Red brome)*
    sitchensis var. carinatus (California brome)
    sitchensis var. marginatus (Mountain brome)
    sitchensis var. maritimus (Seaside brome)
    tectorum (Cheat grass)*
    trinii, see Bromus berteroanus
Buddleja utahensis (Panamint butterfly bush)
Bursera microphylla (Elephant tree)
Caesalpinia
    gilliesii (Yellow bird-of-paradise)*
    virgata, see Hoffmanseggia microphylla
Cakile maritima (Sea rocket)*
Calamagrostis purpurascens (Purple reedgrass)
Calandrinia
    ambigua, see Cistanthe ambigua
    breweri (Brewer's red maids)
    ciliata, see Calandrinia menziesii
    maritima, see Cistanthe maritima
    menziesii (Red maids)
California macrophylla (White-flowered filaree)
Calliandra
    eriophylla (Pink fairy duster)
Callitriche
    heterophylla var. bolanderi (Water-starwort)
    palustris (Vernal water-starwort)
Calocedrus decurrens (Incense-cedar)
Calochortus
    albus (Fairy lantern)
    catalinae (Catalina mariposa lily)
    clavatus var. pallidus (Yellow mariposa lily)
    clavatus var. gracilis (Slender mariposa lily)
    concolor (Golden bowl mariposa lily)
    dunnii (Dunn's mariposa lily)
    fimbriatus (Late-flowering mariposa lily)
    flexuosus (Winding mariposa lily)
    invenustus (Plain mariposa lily)
    kennedyi var. kennedyi (Red mariposa lily)
    kennedyi var. munzii (Desert mariposa lily)
    palmeri var. munzii (Munz's mariposa lily)
    palmeri var. palmeri (Palmer's mariposa lily)
    plummerae (Plummer's mariposa lily)
    splendens (Splendid mariposa lily)
    striatus (Alkali mariposa lily)
    venustus (Butterfly mariposa lily)
    weedii var. intermedius (Intermediate mariposa lily)
    weedii var. vestus, see Calochortus fimbriatus
    weedii var. weedii (Weed's mariposa lily)
Calycanthus occidentalis (Spicebush)*
Calycoseris
    parryi (Yellow tackstem)
    wrightii (White tackstem)
Calyptridium
    monandrum (Sand cress)
    monospermum (One-seeded pussypaws)
    parryi var. parryi (Parry's pussypaws)
    pygmaeum (Pygmy pussypaws)
Calystegia
    collina ssp. venusta (Coast range bindweed)
    macrostegia ssp. amplissima (Southern island morning glory)
    macrostegia ssp. arida (Southern California morning glory)
    macrostegia ssp. cyclostegia (Coast morning glory)
    macrostegia ssp. macrostegia (Northern island morning glory)
    malacophylla ssp. pedicellata (Jepson's morning glory)
    occidentalis ssp. fulcrata (Western morning glory)
    peirsonii (Peirson's morning glory)
    soldanella (Beach morning glory)
Camissonia
    bistorta, see Camissoniopsis bistorta
    boothii ssp. condensata, see Eremothera boothii ssp. condensata
    boothii ssp. decorticans, see Eremothera boothii ssp. decorticans
    boothii ssp. desertorum, see Eremothera boothii ssp. desertorum
    boothii ssp. intermedia, see Eremothera boothii ssp. intermedia
    brevipes ssp. brevipes, see Chylismia brevipes ssp. brevipes
    californica, see Eulobus californicus
    campestris ssp. campestris (Mojave sun cup)
    cardiophylla ssp. cardiophylla, see Chylismia cardiophylla ssp. cardiophylla
    cheiranthifolia ssp. cheiranthifolia, see Camissoniopsis cheiranthifolia ssp. cheiranthifolia
    cheiranthifolia ssp. suffruticosa, see Camissoniopsis cheiranthifolia ssp. suffruticosa
    claviformis ssp. aurantiaca, see Chylismia claviformis ssp. aurantiaca
    claviformis ssp. claviformis, see Chylismia claviformis ssp. claviformis
    claviformis ssp. funerea, see Chylismia claviformis ssp. funerea
    claviformis ssp. lancifolia, see Chylismia claviformis ssp. lancifolia
    claviformis ssp. peirsonii, see Chylismia claviformis ssp. peirsonii
    confusa, see Camissoniopsis confusa
    hirtella, see Camissoniopsis hirtella
    intermedia, see Camissoniopsis intermedia
    kernensis ssp. gilmanii (Kern sun cup)
    lewisii (Lewis's sun cup)
    micrantha, see Camissoniopsis micrantha
    pallida ssp. pallida, see Camissoniopsis pallida ssp. pallida
    palmeri, see Tetrapteron palmeri
    pterosperma, see Chylismiella pterosperma
    pusilla (Little wiry sun cup)
    refracta, see Eremothera refracta
    robusta, see Camissoniopsis robusta
    strigulosa (Strigose sun cup)
    walkeri ssp. tortilis, see Chylismia walkeri ssp. tortilis
Camissoniopsis
    bistorta (Common sun cup)
    cheiranthifolia ssp. cheiranthifolia (Channel Islands beach primrose)
    cheiranthifolia ssp. suffruticosa (Beach primrose)
    confusa (San Bernardino sun cup)
    hirtella (Hairy sun cup)
    ignota (Jurupa Hills sun cup)
    intermedia (Intermediate sun cup)
    micrantha (Small evening primrose)
    pallida ssp. pallida (Pale primrose)
    robusta (Robust sun cup)
Canbya candida (Pygmy poppy)
Capsella bursa-pastoris (Shepherd's purse)*
Cardamine
    californica (Milkmaids)
    oligosperma (Bitter cress)
Cardionema ramosissimum (Sandmat)
Carduus pycnocephalus ssp. pycnocephalus (Italian thistle)*
Carex
    alma (Sturdy sedge)
    aurea (Golden sedge)
    bolanderi (Bolander's sedge)
    densa (Dense sedge)
    filifolia var. erostrata (Sagebrush sedge)
    fracta (Fragile-sheathed sedge)
    heteroneura (Smooth-fruited sedge)
    multicaulis (Forest sedge)
    pellita (Woolly sedge)
    praegracilis (Clustered field sedge)
    rossii (Ross's sedge)
    senta (Western rough sedge)
    spissa (San Diego sedge)
    subfusca (Rusty slender sedge)
    triquetra (Triangular-fruit sedge)
Carlowrightia arizonica (Arizona carlowrightia)
Carnegiea gigantea (Giant saguaro)
Carpenteria californica (Bush anemone)*
Carpobrotus
    chilensis (Sea fig)*
    edulis (Hottentot fig)*
Carthamus tinctorius (Safflower)*
Castela emoryi (Crucifixion thorn)
Castilleja
    affinis ssp. affinis (Coast paintbrush)
    angustifolia, see Castilleja chromosa
    applegatei ssp. martinii (Martin's paintbrush)
    chromosa (Desert paintbrush)
    cinerea (Ashy-gray paintbrush)
    densiflora ssp. gracilis (Dense-flowered owl's clover)
    exserta ssp. exserta (Purple owl's clover)
    exserta ssp. venusta (Mojave owl's clover)
    foliolosa (Woolly paintbrush)
    gleasoni (Mount Gleason paintbrush)
    hololeuca (Island paintbrush)
    lanata ssp. hololeuca, see Castilleja hololeuca
    lasiorhyncha (San Bernardino Mountains owl's clover)
    linariifolia (Narrow-leaved paintbrush)
    miniata ssp. miniata (Great red paintbrush)
    minor ssp. spiralis (Lesser paintbrush)
    mollis (Soft-leaved paintbrush)
    montigena (Heckard's paintbrush)
    nana (Dwarf alpine paintbrush)
    plagiotoma (Yellow paintbrush)
    subinclusa ssp. subinclusa (Longleaf paintbrush)
    tenuis (Hairy owl's clover)
Caulanthus
    amplexicaulis (Clasping-leaved caulanthus)
    anceps (Lemmon's mustard)
    cooperi (Cooper's jewelflower)
    coulteri (Coulter's jewelflower)
    crassicaulis (Thickstem wild cabbage)
    hallii (Hall's caulanthus)
    heterophyllus (Slender-pod jewelflower)
    inflatus (Desert candle)
    lasiophyllus (California mustard)
    major (Slender wild cabbage)
    simulans (Payson's jewelflower)
Ceanothus
    arboreus (Island ceanothus)
    cordulatus (Mountain whitethorn)
    crassifolius var. crassifolius (Hoaryleaf ceanothus)
    cuneatus var. cuneatus (Buckbrush)
    cyaneus (Lakeside ceanothus)
    greggii var. perplexans, see Ceanothus perplexans
    greggii var. vestitus, see Ceanothus pauciflorus
    integerrimus var. macrothyrsus (Deerbrush)
    leucodermis (Chaparral whitethorn)
    megacarpus var. megacarpus (Big-pod ceanothus)
    oliganthus var. oliganthus (Hairy ceanothus)
    palmeri (Palmer's ceanothus)
    papillosus (Wartleaf ceanothus)
    perplexans (Cupleaf ceanothus)
    pauciflorus (Mojave ceanothus)
    spinosus (Greenbark ceanothus)
    tomentosus (Woollyleaf ceanothus)
    verrucosus (Wartstem ceanothus)
Celtis reticulata (Western hackberry)
Centaurea
    benedictus (Blessed thistle)*
    maculosa, see Centaurea stoebe ssp. micranthos
    melitensis (Tocalote)*
    solstitialis (Yellow star thistle)*
    stoebe ssp. micranthos (Spotted knapweed)*
Centaurium venustum, see Zeltnera venusta
Centranthus ruber (Red valerian)*
Centromadia
    parryi ssp. australis (Southern tarplant)
    pungens ssp. laevis (Smooth tarplant)
    pungens ssp. pungens (Spikeweed)
Centrostegia thurberi (Thurber's spineflower)
Centunculus minimus, see Anagallis minima
Cerastium
    fontanum ssp. vulgare (Perennial chickweed)*
    glomeratum (Mouse-ear chickweed)*
Cercidium
    floridum ssp. floridum, see Parkinsonia florida
    microphyllum. see Parkinsonia microphylla
Cercis occidentalis (Western redbud)
Cercocarpus
    betuloides var. betuloides (Birch-leaf mountain-mahogany)
    betuloides var. blancheae (Island mountain-mahogany)
    intricatus, see Cercocarpus ledifolius var. intricatus
    ledifolius var. intricatus (Little-leaved mountain-mahogany)
    ledifolius var. intermontanus (Curl-leaf mountain-mahogany)
    minutiflorus (San Diego mountain-mahogany)
    traskiae (Catalina Island mountain-mahogany)
Chaenactis
    artemisiifolia (White pincushion)
    carphoclinia var. carphoclinia (Pebble pincushion)
    douglasii var. douglasii (Dusty maidens)
    fremontii (Fremont's pincushion)
    glabriuscula var. glabriuscula (Yellow pincushion)
    glabriuscula var. orcuttiana (Orcutt's yellow pincushion)
    macrantha (Large-flowered pincushion)
    santolinoides (Santolina pincushion)
    stevioides (Desert pincushion)
    xantiana (Xantus pincushion)
Chaetadelpha wheeleri (Dune broom)
Chaetopappa ericoides (Rose heath)
Chamaebatia australis (Southern mountain misery)
Chamaebatiaria millefolium (Desert sweet)
Chamaesyce
    abramsiana, see Euphorbia ambramsiana
    albomarginata, see Euphorbia albomarginata
    arizonica, see Euphorbia arizonica
    melanadenia, see Euphorbia melanadenia
    micromera, see Euphorbia micromera
    ocellata ssp. arenicola, see Euphorbia ocellata ssp. arenicola
    parishii, see Euphorbia parishii
    parryi, see Euphorbia parryi
    pediculifera, see Euphorbia pediculifera
    polycarpa, see Euphorbia polycarpa
    prostrata, see Euphorbia prostrata
    serpyllifolia ssp. serpyllifolia, see Euphorbia serpyllifolia ssp. serpyllifolia
    setiloba, see Euphorbia setiloba
Chamerion angustifolium ssp. circumvagum (Fireweed)
Chamomilla suaveolens, see Matricaria matricarioides
Chasmanthe floribunda (South African cornflag)*
Cheilanthes
    clevelandii, see Myriopteris clevelandii
    cooperae, see Myriopteris cooperae
    covillei, see Myriopteris covillei
    feei, see Myriopteris gracilis
    newberryi, see Myriopteris newberryi
    parryi, see Myriopteris parryi
    viscida, see Myriopteris viscida
Chenopodium
    album (Lamb's quarters)*
    ambrosioides, see Dysphania ambrosioides
    atrovirens (Forest goosefoot)
    berlandieri (Pitseed goosefoot)
    botrys, see Dysphania botrys
    californicum (California goosefoot)
    desiccatum (Aridland goosefoot)
    fremontii (Fremont's goosefoot)
    hians (Gaping goosefoot)
    macrospermum (Coast goosefoot)*
    murale (Nettleleaf goosefoot)*
    pratericola (Meadow goosefoot)
Chilopsis linearis ssp. arcuata (Desert willow)
Chimaphila
    menziesii (Little prince's pine)
    umbellata (Pipsissewa)
Chloracantha spinosa var. spinosa (Spiny aster)
Chlorogalum
    parviflorum, see Hooveria parviflora
    pomeridianum var. pomeridianum (Soap plant)
Chloropyron
    maritimum ssp. maritimum (Salt marsh bird's beak)
    tecopense (Tecopa bird's beak)
Chondrilla juncea (Hogbite)*
Chorispora tenella (Crossflower)*
Chorizanthe
    brevicornu var. brevicornu (Brittle spineflower)
    corrugata (Wrinkled spineflower)
    fimbriata var. fimbriata (Fringed spineflower)
    fimbriata var. laciniata (Lace-fringed spineflower)
    leptotheca (Peninsular spineflower)
    membranacea (Pink spineflower)
    parryi var. fernandina (San Fernando Valley spineflower)
    procumbens (Prostrate spineflower)
    rigida (Rigid spineflower)
    spinosa (Mojave spineflower)
    staticoides (Turkish rugging)
    watsonii (Five-tooth spineflower)
    xanti var. leucotheca (Riverside spineflower)
    xanti var. xanti (Xantus' spineflower)
Chrysanthemum coronarium, see Glebionis coronaria
Chrysolepis sempervirens (Bush chinquapin)
Chrysothamnus
    nauseosus ssp. bernardinus, see Ericameria nauseosa var. bernardina
    nauseosus ssp. ceruminosus, see Ericameria nauseosa var. ceruminosa
    nauseosus ssp. consimilis, see Ericameria nauseosa var. oreophila
    nauseosus ssp. hololeucus, see Ericameria nauseosa var. hololeuca
    nauseosus ssp. mohavensis, see Ericameria nauseosa var. mohavensis
    paniculatus, see Ericameria paniculata
    parryi ssp. asper, see Ericameria parryi var. aspera
    teretifolius, see Ericameria teretifolia
    viscidiflorus ssp. viscidiflorus (Sticky-leaved rabbitbrush)
Chylismia
    brevipes ssp. brevipes (Yellow cups)
    cardiophyla ssp. cardiophylla (Heartleaf sun cup)
    cardiophylla ssp. robusta (Robust heartleaf sun cup)
    claviformis ssp. aurantiaca (Browneyes)
    claviformis ssp. claviformis (Mojave brown-eyed primrose)
    claviformis ssp. funerea (Death Valley brown-eyed primrose)
    claviformis ssp. lancifolia (Lanceleaf browneyes)
    claviformis ssp. peirsonii (Peirson's brown-eyed primrose)
    walkeri ssp. tortilis (Walker's sun cup)
Chylismiella pterosperma (Wingfruit sun cup)
Cichorium intybus (Chicory)*
Cirsium
    arizonicum var. tenuisectum (Red thistle)
    mohavense (Mojave thistle)
    neomexicanum (Desert thistle)
    nidulum, see Cirsium arizonicum var. tenuisectum
    occidentale var. californicum (California thistle)
    occidentale var. occidentale (Cobweb thistle)
    occidentale var. venustum (Venus thistle)
    scariosum var. citrinum (Southern meadow thistle)
    scariosum var. congdonii (Elk thistle)
    vulgare (Bull thistle)*
Cistanthe
    ambigua (Desert pot-herb)
    maritima (Seaside red maids)
Cistus
    creticus, see Cistus incanus
    incanus (Pink rock-rose)*
    ladanifer var. albiflorus (White-flowered rock-rose)*
    ladanifer var. maculatus (Crimson spot rock-rose)*
    Xpurpureus (Orchid rock-rose)*
Cladium californicum (California sawgrass)
Clarkia
    bottae (Punchbowl clarkia)
    cylindrica ssp. clavicarpa (Club-fruited speckled clarkia)
    cylindrica ssp. cylindrica (Speckled clarkia)
    dudleyana (Dudley's clarkia)
    epilobioides (Canyon clarkia)
    heterandra (Mountain clarkia)
    purpurea ssp. quadrivulnera (Purple clarkia)
    rhomboidea (Diamond-petalled clarkia)
    similis (Ramona clarkia)
    speciosa ssp. polyantha (Red spot clarkia)
    unguiculata (Elegant clarkia)
    xantiana ssp. xantiana (Gunsight fairyfan)
Claytonia
    exigua ssp. exigua (Little spring beauty)
    gypsophiloides (Gypsum spring beauty)
    parviflora ssp. parviflora (Narrow-leaf miner's lettuce)
    parviflora ssp. utahensis (Utah miner's lettuce)
    parviflora ssp. viridis (Green miner's lettuce)
    peirsonii ssp. peirsonii (Peirson's spring beauty)
    perfoliata ssp. mexicana (Southern miner's lettuce)
    perfoliata ssp. perfoliata (Miners' lettuce)
    rubra ssp. rubra (Redstem spring beauty)
Clematis
    lasiantha (Pipestems)
    ligusticifolia (Virgin's bower)
    pauciflora (Ropevine)
Cleomella
    arborea var. arborea (Bladderpod)
    arborea var. globosa (Round-fruited bladderpod)
    obtusifolia (Mojave stinkweed)
    oxystyloides (False-clover)
    sparsifolia (Naked cleome)
Clinopodium
    chandleri (San Diego satureja)
    douglasii (Yerba buena)
    mimuloides (Monkeyflower savory)
Cneoridium dumosum (Bushrue)
Cnicus benedictus, see Centaurea benedictus
Coleogyne ramosissima (Blackbrush)
Collinsia
    bartsiifolia var. davidsonii (Davidson's blue-eyed mary)
    callosa (Desert collinsia)
    childii (Child's collinsia)
    concolor (Southern Chinese houses)
    heterophylla var. austromontana (Downy Chinese houses)
    heterophylla var. heterophylla (Chinese houses)
    parryi (Parry's collinsia)
    parviflora (Small-flowered collinsia)
    tinctoria (Sticky Chinese houses)
    torreyi var. wrightii (Wright's collinsia)
Collomia
    grandiflora (Large-flowered collomia)
    linearis (Slenderleaf collomia)
Colutea arborescens (Bladder senna)*
Comandra umbellata ssp. californica (California bastard toadflax)
Comarostaphylis
    diversifolia ssp. diversifolia (Varied-leaf summer-holly)
    diversifolia ssp. planifolia (Flat-leaf summer-holly)
Condea emoryi (Desert lavender)
Conium maculatum (Poison hemlock)*
Constancea nevinii (Nevin's woolly sunflower)
Convolvulus
    arvensis (Bindweed)*
    simulans (Small-flowered morning glory)
Conyza
    bonariensis*, see Erigeron bonariensis
    canadensis, see Erigeron canadensis
    coulteri, see Laennecia coulteri
    floribunda*, see Erigeron sumatrensis
Corallorhiza maculata (Spotted coralroot)
Cordylanthus
    maritimus ssp. maritimus, see Chloropyron maritimum ssp. maritimum
    nevinii (Nevin's bird's beak)
    orcuttianus (Orcutt's bird's beak)
    parviflorus (Purple bird's beak)
    rigidus ssp. rigidus (Stiffbranch bird's beak)
    rigidus ssp. setiger (Bristly bird's beak)
Coreopsis
    bigelovii, see Leptosyne bigelovii
    californica var. californica, see Leptosyne californica
    gigantea, see Leptosyne gigantea
    maritima, see Leptosyne maritima
Corethrogyne filaginifolia (California-aster)
Cornus
    nuttallii (Mountain dogwood)
    sericea ssp. sericea (American dogwood)
Coronopus didymus, see Lepidium didymum
Cortaderia selloana (Pampas grass)*
Cosmos bipinnatus (Mexican aster)*
Cotula
    australis (Australian brass buttons)*
    coronopifolia (Brass buttons)*
Crassula
    aquatica (Water pygmyweed)
    colligata ssp. lamprosperma (Australian pygmyweed)*
    connata (Pygmyweed)
    tillaea (Moss pygmyweed)*
Crepis
    acuminata (Tall hawksbeard)
    nana (Dwarf hawksbeard)
    occidentalis (Western hawksbeard)
Cressa truxillensis (Alkali weed)
Crocanthemum scoparium var. vulgare (Peak rush-rose)
Crossosoma
    bigelovii (Rock crossosoma)
    californicum (Catalina crossosoma)
Croton
    californicus (California croton)
    setiger (Doveweed)
    wigginsii (Wiggins's croton)
Cryptantha
    angustifolia (Narrow-leaved cryptantha)
    barbigera var. barbigera (Bearded cryptantha)
    barbigera var. fergusoniae (Ferguson's bearded cryptantha)
    cinerea var. abortiva, see Oreocarya abortiva
    circumscissa var. circumscissa, see Greeneocharis circumscissa var. circumscissa
    clevelandii (Cleveland's cryptantha)
    confertiflora, see Oreocarya confertiflora
    costata, see Johnstonella costata
    decipiens (Gravel cryptantha)
    dumetorum (Bush-loving cryptantha)
    flavoculata, see Oreocarya flavoculata
    gracilis (Slender cryptantha)
    holoptera, see Johnstonella holoptera
    intermedia var. intermedia (Large-flowered cryptantha)
    juniperensis (Rigid cryptantha)
    maritima (Guadalupe cryptantha)
    micrantha var. lepida, see Eremocarya lepida
    micrantha var. micrantha, see Eremocarya micrantha var.micrantha
    micromeres (Minute-flowered cryptantha)
    microstachys (Tejon cryptantha)
    mohavensis (Mojave cryptantha)
    muricata var. denticulata (Prickly-nut cryptantha)
    muricata var. jonesii (Jones' cryptantha)
    muricata var. muricata (Showy cryptantha)
    nevadensis (Nevada cryptantha)
    oxygona (Sharpnut cryptantha)
    pterocarya (Wingnut cryptantha)
    racemosa, see Johnstonella racemosa
    recurvata (Curvenut cryptantha)
    similis, see Greeneocharis similis
    simulans (Pinewoods cryptantha)
    tumulosa, see Oreocarya tumulosa
    utahensis (Scented cryptantha)
    virginensis, see Oreocarya virginensis
Cryptogramma acrostichoides (American rock-brake)
Cucurbita
    foetidissima (Calabazilla)
    palmata (Coyote melon)
Cupressus
    arizonica ssp. arizonica, see Hesperocyparis stephensonii
    forbesii, see Hesperocyparis forbesii
Cuscuta
    californica var. breviflora. see Cuscuta occidentalis
    californica var. californica (California dodder)
    californica var. papillosa (Papillate dodder)
    campestris (Western field dodder)
    denticulata (Desert dodder)
    occidentalis (Short-flowered California dodder)
    pacifica var. pacifica (Salt marsh dodder)
    pentagona, see Cuscuta campestris
    subinclusa (Canyon dodder)
Cusickiella douglasii (Alkali draba)
Cycladenia humilis var. venusta (Showy cycladenia)
Cylindropuntia
    acanthocarpa var. acanthocarpa (Buckhorn cholla)
    bernardina (Valley cholla)
    bigelovii (Jumping cholla)
    echinocarpa (Silver cholla)
    fosbergii (Fosberg's cholla)
    ganderi (Gander's cholla)
    munzii (Munz's cholla)
    prolifera (Coast cholla)
    ramosissima (Pencil cholla)
    wolfii (Wolf's cholla)
Cymopterus
    aboriginum (Spring-parsley)
    gilmanii (Gilman's cymopterus)
    multinervatus (Arizona springparsley)
Cynara cardunculus ssp. flavescens (Cardoon)*
Cynodon dactylon (Bermuda grass)*
Cynoglossum grande, see Adelinia grandis
Cyperus
    eragrostis (Tall flat sedge)
    involucratus (Umbrella plant)*
    laevigatus (Smooth flatsedge)
Cystopteris fragilis (Brittle fern)
Cytisus striatus (Portuguese broom)*
Dactylis glomerata (Orchard grass)*
Dalea
    mollis (Silky dalea)
    mollissima (Downy dalea)
    searlsiae (Searls' prairie clover)
Dasyochloa pulchella (Fluff grass)
Datisca glomerata (Durango root)
Datura
    discolor (Desert thornapple)
    stramonium (Jimsonweed)*
    wrightii (Sacred datura)
Daucus pusillis (American wild carrot)
Dedeckera eurekensis (July gold)
Deinandra
    arida (Red Rock tarplant)
    clementina (Island tarplant)
    conjugens (Otay tarplant)
    fasciculata (Slender tarplant)
    kelloggii (Kellogg's tarplant)
    minthornii (Santa Susana tarplant)
    mohavensis (Mojave tarplant)
    pallida (Kern tarplant)
    paniculata (San Diego tarplant)
Delairea odorata (Cape-ivy)*
Delphinium
    cardinale (Scarlet larkspur)
    glaucum (Mountain larkspur)
    gypsophilum (Gypsum-loving larkspur)
    hansenii ssp. kernense (Kern larkspur)
    parishii ssp. pallidum (Pale larkspur)
    parishii ssp. parishii (Desert larkspur)
    parishii ssp. subglobosum (Colorado Desert larkspur)
    parryi ssp. parryi (Blue larkspur)
    patens ssp. hepaticoideum (Spreading larkspur)
    patens ssp. montanum (Mountain spreading larkspur)
Dendromecon
    harfordii (Channel Island tree poppy)
    rigida (Bush poppy)
Deschampsia elongata (Slender hairgrass)
Descurainia
    californica (Sierra tansy mustard)
    incana (Appressed-fruited mountain tansy mustard)
    incisa ssp. incisa (Mountain tansy mustard)
    pinnata ssp. brachycarpa (Western tansy mustard)
    pinnata ssp. glabra (Tansy mustard)
    sophia (Flix weed)*
Dicentra
    chrysantha, see Ehrendorferia chrysantha
    ochroleuca, see Ehrendorferia ochroleuca
Dichelostemma, see Dipterostemon
Dichondra occidentalis (Western dichondra)
Dicoria canescens (Desert dicoria)
Dicranostegia  orcuttiana (Orcutt's bird's beak)
Dieteria
    asteroides var. asteroides (Scrub aster)
    asteroides var. lagunensis (Laguna Mountains aster)
    canescens var. canescens (Hoary-aster)
    canescens var. leucanthemifolia (Desert hoary-aster)
    canescens var. ziegleri (Ziegler's aster)
Digitalis purpurea (Foxglove)*
Dimorphotheca ecklonis (African daisy)*
Diplacus
    aridus (Low bush monkeyflower)
    australis (Southern bush monkeyflower)
    bigelovii var. bigelovii (Bigelow's monkeyflower)
    bigelovii var. cuspidatus (Northern desert monkeyflower)
    bolanderi (Bolander's monkeyflower)
    brevipes (Yellow monkeyflower)
    calycinus (Southern Sierra bush monkeyflower)
    clevelandii (Cleveland's bush monkeyflower)
    congdonii (Congdon's monkeyflower)
    constrictus (Dense-fruited monkeyflower)
    fremontii (Fremont's monkeyflower)
    johnstonii (Johnston's monkeyflower)
    longiflorus (Hairy bush monkeyflower)
    parviflorus (Island bush monkeyflower)
    pictus (Calico monkeyflower)
    puniceus (Red bush monkeyflower)
    rupicola (Death Valley monkeyflower)
Dipterostemon
    capitatus ssp. capitatus (Blue dicks)
    capitatus ssp. pauciflorus (Few-flowered blue dicks)
Distichlis
    littoralis (Shore grass)
    spicata (Salt grass)
Ditaxis
    lanceolata (Narrow-leaf ditaxis)
    neomexicana (New mexico ditaxis)
Dithyrea californica (Spectacle pod)
Dodecatheon, see Primula
Downingia
    bella (Spotted downingia)
    cuspidata (Toothed calicoflower)
Draba
    albertina (Slender draba)
    corrugata (Southern California draba)
    cuneifolia (California draba)
    saxosa (Southern California rock draba)
    verna (Spring draba)
Drymocallis
    cuneifolia var. ewanii (Ewan's cinquefoil)
    glandulosa var. glandulosa (Inland sticky cinquefoil)
    glandulosa var. reflexa (Double-toothed sticky cinquefoil)
    glandulosa var. viscida (Single-toothed sticky cinquefoil)
    glandulosa var. wrangelliana (Coastal sticky cinquefoil)
    lactea var. lactea (Nevada cinquefoil)
Dryopteris arguta (Coastal wood fern)
Duchesnea indica var. indica (Mock-strawberry)*
Dudleya
    abramsii ssp. affinis (San Bernardino Mountains dudleya)
    arizonica (Arizona chalk dudleya)
    attenuata ssp. orcuttii (Orcutt's dudleya)
    caespitosa (Sand-lettuce)
    candelabrum (Candleholder dudleya)
    cymosa ssp. agourensis (Agoura dudleya)
    cymosa ssp. crebrifolia (San Gabriel River dudleya)
    cymosa ssp. cymosa (Canyon dudleya)
    cymosa ssp. pumila (Low canyon dudleya)
    densiflora (San Gabriel Mountains dudleya)
    edulis (Ladies' fingers)
    greenei (Greene's dudleya)
    hassei, see Dudleya virens ssp. hassei
    lanceolata (Lanceleaf dudleya)
    multicaulis (Many-stemmed dudleya)
    pulverulenta (Chalk dudleya)
    saxosa ssp. aloides (Rock dudleya)
    traskiae (Santa Barbara Island dudleya)
    variegata (Variegated dudleya)
    virens ssp. hassei (Hasse's dudleya)
    viscida (Sticky dudleya)
Dysphania
    ambrosioides (Mexican-tea)*
    botrys (Jerusalem-oak goosefoot )*
Echinocactus polycephalus var. polycephalus (Cottontop cactus)
Echinocereus
    engelmannii (Engelmann's hedgehog cactus)
    mojavensis (Mojave mound cactus)
    triglochidiatus, see Echinocereus mohavensis
Echinodorus berteroi (Burhead)
Eclipta prostrata (False-daisy)
Ehrendorferia
    chrysantha (Golden eardrops)
    ochroleuca (Bleeding hearts)
Eleocharis
    acicularis var. acicularis (Needle spikerush)
    macrostachya (Common spikerush)
    montevidensis (Sand spikerush)
Elodea nuttallii (Western waterweed)
Elymus
    cinereus (Great Basin wildrye)
    condensatus (Giant wildrye)
    elymoides ssp. brevifolius (Short-leaved squirreltail)
    elymoides ssp. californicus (California squirreltail)
    glaucus ssp. glaucus (Blue wildrye)
    hispidus (Intermediate wheat grass)*
    pacificus (Pacific wildrye)
    ponticus (Tall wheat grass)*
    trachycaulus ssp. trachycaulus (Slender wheat grass)
    triticoides (Creeping wildrye)
Elytrigia
    intermedia ssp. intermedia, see Elymus hispidus
    pontica ssp. pontica, see Elymus ponticus
Emex spinosa (Devil's thorn)*
Emmenanthe penduliflora (Whispering bells)
Encelia
    actoni (Acton encelia)
    californica (Bush sunflower)
    farinosa (Brittlebush)
    frutescens (Rayless encelia)
    virginensis (Green encelia)
Enceliopsis
    covillei (Panamint daisy)
    nudicaulis (Sunray)
Ephedra
    aspera (Rough joint-fir)
    californica (California ephedra)
    nevadensis (Nevada ephedra)
    viridis (Green ephedra)
Epilobium
    angustifolium ssp. circumvagum, see Chamerion angustifolium ssp. circumvagum
    brachycarpum (Field willow-herb)
    campestre (Smooth boisduvalia)
    canum ssp. canum (Hoary fuchsia)
    canum ssp. latifolium (California fuchsia)
    ciliatum ssp. ciliatum (Willow-herb)
    ciliatum ssp. glandulosum (Glandular willow-herb)
    densiflorum (Spike primrose)
    glaberrimum ssp. glaberrimum (Smooth willow-herb)
    hallianum (Hall's willow-herb)
    lactiflorum (Milkflower willow-herb)
    oregonense (Oregon willow-herb)
    pygmaeum, see Epilobium campestre
Epipactis gigantea (Stream orchid)
Equisetum
    arvense (Common horsetail)
    hyemale ssp. affine (Common scouring rush)
    laevigatum (Smooth scouring rush)
    telmateia ssp. braunii (Giant horsetail)
Eragrostis curvula (Weeping love grass)*
Eremalche
    exilis (White mallow)
    parryi ssp. kernensis (Kern mallow)
    rotundifolia (Desert fivespot)
Eremocarpus setigerus, see Croton setiger
Eremocarya
    lepida (Mountain red-root cryptantha)
    micrantha var. micrantha (Red-root cryptantha)
Eremogone
    kingii var. glabrescens (King's sandwort)
    macradenia var. arcuifolia (Forest camp sandwort)
    macradenia var. macradenia (Desert sandwort)
    ursina (Bear valley sandwort)
Eremothera
    boothii ssp. condensata (Booth's clustered evening primrose)
    boothii ssp. decorticans (Booth's shredding evening primrose)
    boothii ssp. desertorum (Booth's desert evening primrose)
    boothii ssp. intermedia (Booth's intermediate evening primrose)
    chamaenerioides (Longfruit sun cup)
    refracta (Narrow-leaf suncup)
Eriastrum
    densifolium ssp. austromontanum (Southern mountain woolstar)
    densifolium ssp. elongatum (Giant woolstar)
    densifolium ssp. mohavense (Mojave woolstar)
    densifolium ssp. sanctorum (Santa Ana River woolstar)
    diffusum (Miniature woolstar)
    eremicum ssp. eremicum (Desert woolstar)
    harwoodii (Harwood's woolstar)
    sapphirinum ssp. dasyanthum (Shaggy-flowered woolstar)
    sapphirinum ssp. sappirinum (Sapphire woolstar)
    signatum (Maroon-spotted woolstar)
    sparsiflorum (Few-flowered woolstar)
    tracyi (Tracy's woolstar)
    wilcoxii (Wilcox's woolstar)
Ericameria
    albida (White-flowered rabbitbrush)
    arborescens (Golden-fleece)
    brachylepis (Boundary goldenbush)
    cooperi var. cooperi (Cooper's goldenbush)
    cuneata var. cuneata (Rock goldenbush)
    cuneata var. macrocephala (Laguna Mountains goldenbush)
    cuneata var. spathulata (Wide-leaved rock goldenbush)
    ericoides (Mock heather)
    laricifolia (Turpentine bush)
    linearifolia (Interior goldenbush)
    nana (Dwarf goldenbush)
    nauseosa var. bernardina (San Bernardino rubber rabbitbrush)
    nauseosa var. ceruminosa (Sharp-bracted rubber rabbitbrush)
    nauseosa var. hololeuca (Ghostly rubber rabbitbrush)
    nauseosa var. mohavensis (Mojave rubber rabbitbrush)
    nauseosa var. oreophila (Threadleaf rubber rabbitbrush)
    palmeri var. pachylepis (Palmer's goldenbush)
    paniculata (Black-banded rabbitbrush)
    parishii var. parishii (Parish's goldenbush)
    parryi var. aspera (Parry's rabbitbrush)
    pinifolia (Pine goldenbush)
    teretifolia (Green rabbitbrush)
Erigeron
    aphanactis var. aphanactis (Rayless shaggy fleabane)
    aphanactis var. congestus (Rayless fleabane)
    bonariensis (Small horseweed)*
    breweri var. breweri (Brewer's fleabane)
    breweri var. covillei (Coville's fleabane)
    breweri var. jacinteus (San Jacinto Mountains fleabane)
    breweri var. porphyreticus (Mojave Brewer's fleabane)
    canadensis (Tall horseweed)
    clokeyi var. pinzliae (Pinzl's fleabane)
    compositus (Cutleaf daisy)
    concinnus (Navajo fleabane)
    divergens (Spreading fleabane)
    foliosus var. foliosus (Leafy daisy)
    glaucus (Seaside daisy)
    lonchophyllus (Shortray fleabane)
    parishii (Parish's fleabane)
    sumatrensis (Asthmaweed)*
Eriodictyon
    crassifolium var. crassifolium (Thickleaf yerba santa)
    crassifolium var. nigrescens (Bicolored yerba santa)
    parryi (Poodle-dog bush)
    traskiae ssp. smithii (Trask's yerba santa)
    trichocalyx var. lanatum (San Diego yerba santa)
    trichocalyx var. trichocalyx (Hairy yerba santa)
Eriogonum
    angulosum (Angled-stem buckwheat)
    apiculatum (San Jacinto buckwheat)
    arborescens (Santa Cruz Island buckwheat)
    baileyi var. baileyi (Bailey's buckwheat)
    brachyanthum (Shortflower buckwheat)
    brachypodum (Parry's wild buckwheat)
    callistum (Tehachapi buckwheat)
    cinereum (Ashy-leaf buckwheat)
    cithariforme var. agninum (Santa Ynez wild buckwheat)
    cithariforme var. cithariforme (Cithara wild buckwheat)
    contiguum (Reveal's buckwheat)
    crocatum (Conejo buckwheat )
    davidsonii (Davidson's buckwheat)
    deflexum var. baratum (Tall skeleton weed)
    deflexum var. deflexum (Flatcrown buckwheat)
    deserticola (Dune buckwheat)
    elongatum var. elongatum (Longstem buckwheat)
    eremicola (Wildrose Canyon buckwheat)
    fasciculatum var. fasciculatum (Coastal California buckwheat)
    fasciculatum var. flavoviride (East Mojave buckwheat)
    fasciculatum var. foliolosum (Leafy buckwheat)
    fasciculatum var. polifolium (California wild buckwheat)
    giganteum var. compactum (Santa Barbara Island buckwheat)
    giganteum var. giganteum (St. Catherine's lace)
    gilmanii (Gilman's buckwheat)
    gossypinum (Cottony wild buckwheat)
    gracile var. gracile (Slender buckwheat)
    gracilipes (White Mountains wild buckwheat)
    gracillimum (Rose-and-white buckwheat)
    grande var. grande (Island buckwheat)
    grande var. rubescens (Red-flowered buckwheat)
    heermannii var. argense (Heermann's buckwheat)
    heermannii var. floccosum (Clark Mountains buckwheat)
    heermannii var. heermannii (Large Heermann's buckwheat)
    hoffmannii var. robustius (Robust Hoffmann's buckwheat)
    inflatum (Desert trumpet)
    intrafractum (Jointed buckwheat)
    kennedyi var. alpigenum (Southern alpine buckwheat)
    kennedyi var. austromontanum (Southern mountain buckwheat)
    kennedyi var. kennedyi (Kennedy's buckwheat)
    maculatum (Spotted buckwheat)
    microtheca var. corymbosoides (San Bernardino buckwheat)
    microtheca var. johnstonii (Johnston's buckwheat)
    microtheca var. simpsonii (Simpson's buckwheat)
    molestum (Pineland buckwheat)
    nidularium (Birdnest buckwheat)
    nudum var. pauciflorum (Few-flowered naked buckwheat)
    nudum var. westonii (Weston's buckwheat)
    ordii (Fort Mojave buckwheat)
    ovalifolium var. ovalifolium (Oval-leaved buckwheat)
    ovalifolium var. vineum (Cushenbury buckwheat)
    palmerianum (Palmer's buckwheat)
    panamintense (Panamint buckwheat)
    parishii (Parish's buckwheat)
    parvifolium (Seacliff buckwheat)
    plumatella (Flat-topped buckwheat)
    pusillum (Yellow turban)
    reniforme (Kidneyleaf buckwheat)
    rixfordii (Rixford's buckwheat)
    roseum (Wand buckwheat)
    saxatile (Rock buckwheat)
    thomasii (Thomas' buckwheat)
    thornei (Thorne's buckwheat)
    thurberi (Thurber's buckwheat)
    trichopes (Little desert trumpet)
    umbellatum var. minus (Alpine sulphur-flowered buckwheat)
    umbellatum var. munzii (Munz's buckwheat)
    umbellatum var. nevadense (Nevada buckwheat)
    umbellatum var. subaridum (Sulphur-flowered buckwheat)
    umbellatum var. versicolor (Varicolored buckwheat)
    wrightii var. membranaceum (Ring-stemmed bastard-sage)
    wrightii var. nodosum (Knot-stemmed bastard-sage)
    wrightii var. subscaposum (Short-stemmed bastard-sage)
    wrightii var. wrightii (Wright's bastard-sage)
Erioneuron pulchellum, see Dasyochloa pulchella
Eriophyllum
    ambiguum var. paleaceum (Yellow-frocks)
    confertiflorum var. confertiflorum (Golden yarrow)
    lanatum var. obovatum (Woolly sunflower)
    lanosum (White easter bonnets)
    multicaule (Many-stem woolly sunflower)
    nevinii, see Constancea nevinii
    pringlei (Pringle's woolly sunflower)
    wallacei (Woolly daisy)
Erodium
    botrys (Long-beaked storksbill)*
    brachycarpum (Short-fruited filaree)*
    cicutarium (Red-stem filaree)*
    macrophyllum, see California macrophylla
    moschatum (White-stem filaree)*
    texanum (Desert heron's bill)
Eryngium aristulatum var. parishii (San Diego button-celery)
Erysimum
    capitatum var. capitatum (Western wallflower)
    insulare (Island wallflower)
    suffrutescens (Suffrutescent wallflower)
Erythranthe
    androsacea (Rock-jasmine monkeyflower)
    breweri (Brewer's monkeyflower)
    calcicola (Limestone monkeyflower)
    cardinalis (Scarlet monkeyflower)
    exigua (San Bernardino Mountains monkeyflower)
    floribunda (Many-flowered monkeyflower)
    geniculata (Bent-stem monkeyflower)
    guttata (Creek monkeyflower)
    inconspicua (Smallflower monkeyflower)
    moschata (Musk monkeyflower)
    nasuta (Large-nosed monkeyflower)
    palmeri (Palmer's monkeyflower)
    parishii (Parish's monkeyflower)
    primuloides (Primrose monkeyflower)
    purpurea (Purple monkeyflower)
    rhodopetra (Red Rock Canyon monkeyflower)
    rubella (Red-stemmed monkeyflower)
    shevockii (Kelso Creek monkeyflower)
    sierrae (Sierra Nevada monkeyflower)
    suksdorfii (Suksdorf's monkeyflower)
    tilingii (Tiling's monkeyflower)
Eschscholzia
    caespitosa (Tufted poppy)
    californica (California poppy)
    glyptosperma (Desert gold poppy)
    lemmonii ssp. kernensis (Tejon poppy)
    minutiflora (Little gold poppy)
    parishii (Parish's poppy)
Escobaria
    alversonii (Alverson's spinystar)
    chlorantha (Desert spinystar)
    vivipara var. rosea (Rosy spinystar)
Eucnide
    rupestris (Annual rock-nettle)
    urens (Desert rock-nettle)
Eucrypta
    chrysanthemifolia var. bipinnatifida (Torrey's eucrypta)
    chrysanthemifolia var. chrysanthemifolia (Common eucrypta)
    micrantha (Small-flowered eucrypta)
Eulobus californicus (California sun cup)
Euonymus occidentalis var. parishii (Burning bush)
Euphorbia
    abramsiana (Abrams' spurge)
    albomarginata (Rattlesnake weed)
    arizonica (Arizona spurge)
    characias (Bush spurge)*
    eriantha (Beetle spurge)
    incisa, see Euphorbia schizoloba
    lathyris (Caper spurge)*
    lurida (Woodland spurge)
    melanadenia (Red-gland spurge)
    micromera (Sonoran spurge)
    misera (Cliff spurge)
    ocellata ssp. arenicola (Dune spurge)
    palmeri, see Euphorbia lurida
    parishii (Parish's spurge)
    parryi (Parry's spurge)
    pediculifera (Carrizo Mountain spurge)
    peplus (Petty spurge)*
    polycarpa (Small-seeded spurge)
    prostrata (Prostrate spurge)*
    schizoloba (Mojave spurge)
    serpyllifolia ssp. serpyllifolia (Thyme-leaved spurge)
    setiloba (Yuma spurge)
    spathulata (Warty spurge)
    terracina (Terracina spurge)*
Eustoma exaltatum ssp. exaltatum (Catchfly gentian)
Euthamia occidentalis (Western goldenrod)    
Extriplex californica (California saltbush)
Fagonia
    laevis (Smooth-stemmed fagonia)
    pachyacantha (Sticky fagonia)
Fallugia paradoxa (Apache plume)
Fendlerella utahensis (Utah fendlerbush)
Ferocactus
    cylindraceus (California barrel cactus)
    viridescens (Coast barrel cactus)
Festuca
    arundinacea (Tall fescue)*
    kingii (Spike fescue)
    microstachys (Small fescue)
    myuros (Rattail fescue)*
    octoflora (Six-weeks grass)
    perennis (Ryegrass)*
    rubra (Red fescue)
    temulenta (Darnel)*
Ficus carica (Edible fig)*
Filago
    californica, see Logfia filaginoides
    depressa, see Logfia depressa
    gallica, see Logfia gallica
Foeniculum vulgare (Sweet fennel)*
Forestiera pubescens (Desert olive)
Fouquieria splendens ssp. splendens (Ocotillo)
Fragaria vesca (Wild strawberry)
Frangula 
    californica ssp. californica (Coffeeberry)
    californica ssp. cuspidata (Sierra hoary coffeeberry)
    californica ssp. tomentella (Hoary coffeeberry)
Frankenia
    palmeri (Palmer's frankenia)
    salina (Alkali heath)
Frasera
    neglecta (Pine green-gentian)
    parryi (Parry's green-gentian)
    puberulenta (Inyo frasera)
Fraxinus
    dipetala (California ash)
    velutina (Velvet ash)
Fremontodendron
    californicum (Flannel bush)
    mexicanum (Mexican flannel bush)
Fritillaria
    biflora var. biflora (Chocolate lily)
    ojaiensis (Ojai fritillary)
    pinetorum (Pinewoods fritillary)
    striata (Striped adobe lily)
Funastrum
    cynanchoides var. hartwegii (Climbing milkweed)
    hirtellum (Hairy milkweed)
Galium
    andrewsii ssp. andrewsii (Andrews' bedstraw)
    andrewsii ssp. intermedium (Phlox-leaved bedstraw)
    angustifolium ssp. angustifolium (Narrow-leaved bedstraw)
    angustifolium ssp. foliosum (Island leafy bedstraw)
    angustifolium ssp. gabrielense (San Antonio Canyon bedstraw)
    angustifolium ssp. gracillimum (Slender bedstraw)
    angustifolium ssp. jacinticum (San Jacinto Mountains bedstraw)
    angustifolium ssp. nudicaule (Naked-stem bedstraw)
    aparine (Annual bedstraw)
    bifolium (Twinleaf bedstraw)
    buxifolium (Boxwood-leaved bedstraw)
    californicum ssp. flaccidum (California bedstraw)
    californicum ssp. miguelense (San Miguel Island bedstraw)
    catalinense (Catalina Island bedstraw)
    grande (San Gabriel bedstraw)
    hallii (Nodding bedstraw)
    hilendiae ssp. hilendiae (Hilend's bedstraw)
    jepsonii (Jepson's bedstraw)
    johnstonii (Johnston's bedstraw)
    murale (Tiny bedstraw)*
    nuttallii ssp. insulare (Nuttall's island bedstraw)
    nuttallii ssp. nuttallii (Climbing bedstraw)
    parishii (Parish's bedstraw)
    parisiense (Wall bedstraw)*
    porrigens var. porrigens (Graceful bedstraw)
    stellatum (Star-flowered bedstraw)
    trifidum ssp. columbianum (Sprawling three-petal bedstraw)
    trifidum ssp. subbiflorum (Dwarf three-petal bedstraw)
    wrightii (Wright's bedstraw)
Galvezia speciosa, see Gambelia speciosa
Gambelia speciosa (Showy island snapdragon)
Gamochaeta ustulata (Purple cudweed)
Garrya
    elliptica (Coast silktassel)
    flavescens (Ashy silktassel)
    fremontii (Fremont's silktassel)
    veatchii (Canyon silktassel)
Gastridium
    phleoides (Nit grass)*
    ventricosum, see Gastridium phleoides
Gaura
    coccinea, see Oenothera suffrutescens
    sinuata, see Oenothera sinuosa
Gayophytum
    diffusum ssp. parviflorum (Small-flowered groundsmoke)
    heterozygum (Zig-zag groundsmoke)
    oligospermum (Pinegrove groundsmoke)
Genista
    linifolia (Mediterranean broom)*
    monspessulana (French broom)*
Gentiana fremontii (Moss gentian)
Gentianella amarella ssp. acuta (Autumn dwarf gentian)
Gentianopsis simplex (Hikers' gentian)
Geraea
    canescens (Desert sunflower)
    viscida (Sticky geraea)
Geranium
    californicum (California geranium)
    carolinianum (Carolina geranium)
    dissectum (Cutleaf geranium)*
    molle (Dovefoot geranium)*
    rotundifolium (Roundleaf geranium)*
Geum macrophyllum var. perincisum (Large-leaved avens)
Gilia
    aliquanta ssp. aliquanta (Puff-calyx gilia)
    aliquanta ssp. breviloba (Western gilia)
    angelensis (Chaparral gilia)
    australis, see Saltugilia australis
    brecciarum ssp. brecciarum (Nevada gilia)
    brecciarum ssp. neglecta (Argus gilia)
    campanulata, see Linanthus campanulatus
    cana ssp. bernardina (San Bernardino showy gilia)
    cana ssp. speciformis (Showy gilia)
    cana ssp. triceps (Three-headed showy gilia)
    capitata ssp. abrotanifolia (Globe gilia)
    caruifolia, see Saltugilia caruifolia
    clokeyi (Clokey's gilia)
    diegensis (San Diego gilia)
    filiformis, see Linanthus filiformis
    hutchinsifolia, see Aliciella hutchinsifolia
    jacens (Decumbent gilia)
    latiflora ssp. cuyamensis (Cuyama gilia)
    latiflora ssp. davyi (Davy gilia)
    latiflora ssp. latiflora (Broad-flowered gilia)
    latifolia, see Aliciella latifolia ssp. latifolia
    leptantha ssp. leptantha (Fine-flower gilia)
    leptantha ssp. purpusii (Purpus's gilia)
    leptantha ssp. transversa (Transverse fine-flower gilia)
    maculata, see Linanthus maculatus
    mexicana (El Paso gilia)
    minor (Little gilia)
    modocensis (Modoc gilia)
    ochroleuca ssp. bizonata (Banded volcanic gilia)
    ochroleuca ssp. exilis (Slender volcanic gilia)
    ochroleuca ssp. ochroleuca (Volcanic gilia)
    ochroleuca ssp. vivida (San Gabriel Mountains gilia)
    ophthalmoides (Eyed gilia)
    scopulorum (Rock gilia)
    sinuata (Rosy gilia)
    splendens ssp. grantii, see Saltugilia splendens ssp. grantii
    splendens ssp. splendens, see Saltugilia ssp. splendens
    stellata (Star gilia)
    transmontana (Transmontane gilia)
    tricolor ssp. diffusa (Birdseye gilia)
    triodon, see Aliciella triodon
Githopsis
    diffusa ssp. candida (White-flowered bluecup)
    diffusa ssp. diffusa (San Gabriel bluecup)
Glebionis coronaria (Garland chrysanthemum)*
Glechoma hederacea (Ground ivy)*
Glossopetalon spinescens var. aridum (Spiny greasebush)
Glyceria elata (Fowl mannagrass)
Glycyrrhiza lepidota (Wild licorice)
Glyptopleura marginata (Keysia)
Gnaphalium
    bicolor, see Pseudognaphalium biolettii
    californicum, see Pseudognaphalium californicum
    canescens ssp. beneolens, see Pseudognaphalium beneolens
    canescens ssp. canescens, see Pseudognaphalium canescens
    canescens ssp. microcephalum, see Pseudognaphalium microcephalum
    canescens ssp. thermale, see Pseudognaphalium thermale
    luteo-album, see Pseudognaphalium luteoalbum
    palustre (Lowland cudweed)
    purpureum, see Gamochaeta ustulata
    ramosissimum, see Pseudognaphalium ramosissimum
    stramineum, see Pseudognaphalium stramineum
Grayia spinosa (Spiny hopsage)
Greeneocharis
    circumscissa var. circumscissa (Cushion cryptantha)
    similis (Desert cryptantha)
Grindelia
    camporum (Common gumplant)
    hallii (San Diego gumplant)
    hirsutula (Hairy gumplant)
    stricta var. platyphylla (Coastal gumplant)
Grusonia parishii (Mat cholla)
Guillenia lasiophylla, see Caulanthus lasiophyllus
Gutierrezia
    californica (California matchweed)
    microcephala (Sticky snakeweed)
    sarothrae (Broom snakeweed)
Halimolobos jaegeri (Rock mustard)
Harpagonella palmeri (Palmer's grappling hook)
Hazardia
    brickellioides (Holly-leaved hazardia)
    detonsa (Island hazardia)
    orcuttii (Orcutt's hazardia)
    squarrosa var. grindelioides (Sawtooth goldenbush)
Hecastocleis shockleyi (Shockley's prickleleaf)
Hedera helix (English ivy)*
Hedeoma
    drummondii (Drummond's false pennyroyal)
    nana ssp. californica (California false pennyroyal)
Hedypnois cretica (Crete weed)*
Helenium
    bigelovii (Bigelow's sneezeweed)
    puberulum (Sneezeweed)
Helianthella californica var. nevadensis (Sierra helianthella)
Helianthemum scoparium, see Crocanthemum scoparium var. vulgare
Helianthus
    annuus (Common sunflower)
    californicus (California sunflower)
    gracilentus (Slender-leaved sunflower)
    niveus ssp. tephrodes (Algodones Dunes sunflower)
    petiolaris ssp. canescens (Dune sunflower)
Heliomeris multiflora var. nevadensis (Nevada goldeneye)
Heliotropium curassavicum var. oculatum (Wild heliotrope)
Helminthotheca echioides (Bristly ox-tongue)*
Hemizonella minima (Pygmy madia)
Hemizonia
    arida, see Deinandra arida
    clementina, see Deinandra clementina
    conjugens, see Deinandra conjugens
    fasciculata, see Deinandra fasciculata
    minthornii, see Deinandra minthornii
    mohavensis, see Deinandra mohavensis
    paniculata, see Deinandra paniculata
    parryi ssp. australis, see Centromadia parryi ssp. australis
    pungens, see Centromadia pungens
Heracleum lanatum, see Heracleum maximum
Heracleum maximum (Cow parsnip)
Herniaria hirsuta var. cinerea (Gray herniaria)*
Hesperevax acaulis var. ambusticola (Stemless evax)
Hesperocallis undulata (Desert lily)
Hesperochiron nanus (California hesperochiron)
Hesperocnide tenella (Black hair nettle)
Hesperocyparis
    stephensonii (Cuyamaca cypress)
    forbesii (Tecate cypress)
Hesperolinon micranthum (Small-flowered dwarf flax)
Hesperoyucca whipplei (Chaparral yucca)
Heterocodon rariflorum (Few-flowered heterocodon)
Heteromeles arbutifolia (Toyon)
Heterotheca
    grandiflora (Telegraph weed)
    sessiliflora ssp. echioides (Bristly golden-aster)
    sessiliflora ssp. fastigiata (Erect golden-aster)
    villosa var. scabra (Rough hairy golden-aster)
Heuchera
    abramsii (Abrams' alumroot)
    brevistaminea (Mount Laguna alumroot)
    caespitosa (Elegant alumroot)
    hirsutissima (Shaggy-haired alumroot)
    maxima (Island alumroot)
    parishii (San Bernardino Mountains alumroot)
    rubescens (Pink alumroot)
Hibiscus denudatus (Rock hibiscus)
Hieracium
    albiflorum (White-flowered hawkweed)
    argutum (Hawkweed)
    horridum (Shaggy hawkweed)
Hilaria rigida (Big galleta grass)
Hirschfeldia incana (Shortpod mustard)*
Hoffmannseggia
    glauca (Hog potato)
    microphylla (Hoffmannseggia)
Hoita
    macrostachya (Leather root)
    orbicularis (Roundleaf leather root)
Hollisteria lanata (False-spineflower)
Holmgrenanthe petrophila (Rock lady)
Holocarpha
    heermannii (Heermann's tarplant)
    virgata ssp. elongata (Graceful tarplant)
Holodiscus
    discolor var. discolor (Cream bush)
    discolor var. microphyllus (Small-leaved cream bush)
    microphyllus var. microphyllus, see Holodiscus discolor var. microphyllus
Hooveria parviflora (Small-flowered soap plant)
Hordeum
    brachyantherum ssp. californicum (Meadow barley)
    intercedens (Bobtail barley)
    murinum ssp. glaucum (Foxtail barley)*
    murinum ssp. leporinum (Hare barley)*
Horkelia
    clevelandii var. clevelandii (Cleveland's horkelia)
    cuneata var. cuneata (Wedge-leaf horkelia)
    hispidula (White Mountains horkelia)
    rydbergii (Rydberg's horkelia)
    truncata (Ramona horkelia)
    wilderae (Barton Flats horkelia)
Hornungia procumbens (Prostrate hutchinsia)
Horsfordia
    alata (Pink velvet-mallow)
    newberryi (Newberry's velvet-mallow)
Hosackia
    crassifolia var. crassifolia (Broad-leaved lotus)
    oblongifolia var. oblongifolia (Streambank lotus)
Hulsea
    algida (Alpine gold hulsea)
    californica (San Diego hulsea)
    heterochroma (Red-rayed hulsea)
    vestita ssp. callicarpha (Beautiful hulsea)
    vestita ssp. gabrielensis (San Gabriel Mountains hulsea)
    vestita ssp. parryi (Parry's hulsea)
    vestita ssp. pygmaea (Pygmy hulsea)
Hutchinsia procumbens, see Hornungia procumbens
Hydrocotyle verticillata (Water pennywort)
Hymenoclea salsola var. salsola, see Ambrosia salsola var. salsola
Hymenopappus
    filifolius var. lugens (Southern mountain cutleaf)
    filifolius var. megacephalus (Fineleaf hymenopappus)
Hymenothrix
    dissecta (Ragged-leaf bahia)
    wrightii (Wright's thimblehead)
Hymenoxys
    acaulis var. arizonica, see Tetraneuris acaulis var. arizonica
    cooperi (Cooper's goldflower)
Hypericum
    anagalloides (Tinker's penny)
    formosum var. scouleri, see Hypericum scouleri
    scouleri (Scouler's St. John's wort)
Hypochaeris
    glabra (Smooth cat's ear)*
    radicata (Rough cat's ear)*
Imperata brevifolia (California satintail)
Ipomopsis
    arizonica (Arizona ipomopsis)
    congesta ssp. montana (Ballhead ipomopsis)
    polycladon (Spreading gilia)
Iris
    douglasiana (Douglas's iris)
    hartwegii ssp. australis (Hartweg's iris )
    missouriensis (Western blue flag)
Isocoma
    acradenia var. bracteosa (Bracted alkali goldenbush)
    acradenia var. eremophila (Solitary-leaved alkali goldenbush)
    menziesii var. decumbens(Decumbent goldenbush)
    menziesii var. menziesii (Menzies' goldenbush)
    menziesii var. sedoides (Prostrate coast goldenbush)
    menziesii var. vernonioides (Coast goldenbush)
Isoetes bolanderi (Bolander's quillwort)
Isomeris arborea, see Peritoma arborea
Iva
    axillaris (Poverty weed)
    hayesiana (Poor man's timothy)
Ivesia
    argyrocoma var. argyrocoma (Silver-haired ivesia)
    callida (Tahquitz ivesia)
    santolinoides (Mousetail ivesia)
    saxosa (Rock ivesia)
Jaumea carnosa (Marsh jaumea)
Jepsonia parryi (Parry's jepsonia)
Johnstonella 
    angustifolia (Narrow-leaved cryptantha)
    costata (Ribbed cryptantha)
    holoptera (Winged cryptantha)
    racemosa (Bushy cryptantha)
Juglans californica (California black walnut)
Juncus
    acutus ssp. leopoldii (Spiny rush)
    balticus (Wire rush)
    bryoides (Moss rush)
    bufonius var. bufonius (Common toad rush)
    bufonius var. congestus (Clustered toad rush)
    bufonius var. occidentalis (Western toad rush)
    cooperi (Cooper's rush)
    covillei (Coville's rush)
    dubius (Mariposa rush)
    effusus ssp. pacificus (Pacific rush)
    macrandrus (Long-anthered rush) 
    macrophyllus (Long-leaved rush)
    mexicanus (Mexican rush)
    orthophyllus (Straightleaf rush)
    patens (Spreading rush)
    phaeocephalus var. paniculatus (Brown-headed rush)
    rugulosus (Wrinkled rush)
    saximontanus (Rocky Mountain rush)
    textilis (Basket rush)
    tiehmii (Tiehm's rush)
    xiphioides (Iris-leaved rush)
Juniperus
    californica (California juniper)
    grandis (Grand juniper)
    occidentalis var. australis, see Juniperus grandis
    osteosperma (Utah juniper)
Justicia
    californica (Chuparosa)
Kallstroemia
    californica (California kallstroemia)
    parviflora (Few-flowered caltrop)
Keckiella
    antirrhinoides var. antirrhinoides (Yellow penstemon)
    antirrhinoides var. microphylla (Little-leaved yellow penstemon)
    breviflora var. breviflora (Gaping penstemon)
    cordifolia (Heartleaf penstemon)
    rothrockii var. jacintensis (San Jacinto Mountains keckiella)
    rothrockii var. rothrockii (Rothrock's keckiella)
    ternata var. septentrionalis (Northern blue-stemmed keckiella)
    ternata var. ternata (Whorl-leaf penstemon)
Kelloggia galioides (Kelloggia)
Kickxia elatine (Sharpleaf cancerwort)*
Koeleria macrantha (Junegrass)
Kopsiopsis strobilacea (California groundcone)
Krameria
    bicolor (White rhatany)
    erecta (Littleleaf rhatany)
    grayi, see Krameria bicolor
Krascheninnikovia lanata (Winterfat)
Lactuca
    saligna (Willowleaf lettuce)*
    serriola (Prickly lettuce)*
Laennecia coulteri (Coulter's horseweed)
Lagophylla ramosissima (Branched hareleaf)
Lamarckia aurea (Goldentop grass)*
Lamium amplexicaule (Henbit)*
Langloisia
    setosissima ssp. punctata (Lilac sunbonnets)
     setosissima ssp. setosissima (Bristly langloisia)
Laphamia megalocephala var. megalocephala (Nevada rock daisy)
Lappula
    redowskii var. cupulata (Stickseed)
    redowskii var. redowskii (Redowski's stickseed)
Larrea tridentata (Creosote bush)
Lastarriaea coriacea (Leather spineflower)
Lasthenia
    californica ssp. californica (California goldfields)
    coronaria (Royal goldfields)
    glaberrima (Rayless goldfields)
    gracilis (Common goldfields)
Lathyrus
    latifolius (Perennial sweet pea)*
    vestitus var. alefeldii (San Diego pea)
    vestitus var. vestitus (Canyon sweet pea)
Lavatera
    assurgentiflora, see Malva assurgentiflora
    cretica, see Malva pseudolavatera
Layia
    glandulosa (White tidy tips)
    hieracioides (Hawkweed layia)
    leucopappa (Comanche Point tidy tips)
    platyglossa (Yellow tidy tips)
Lemna
    minuta (Least duckweed)
    turionifera (Turion duckweed)
Lepechinia
    cardiophylla (Heartleaf pitcher sage)
    fragrans (Fragrant pitcher sage)
Lepidium
    didymum (Wart cress)*
    flavum (Yellow peppergrass)
    fremontii (Desert alyssum)
    lasiocarpum ssp. lasiocarpum (Hairy-podded peppergrass)
    latifolium (Perennial peppergrass)*
    montanum var. cinereum (Mountain peppergrass)
    nitidum (Shiny peppergrass)
    perfoliatum (Clasping pepperweed)*
    virginicum ssp. menziesii (Wild peppergrass)
    virginicum ssp. virginicum (Virginia peppergrass)
Lepidospartum
    latisquamum (Nevada broomsage)
    squamatum (Scalebroom)
Leptodactylon
    californicum, see Linanthus californicus
    jaegeri, see Linanthus jaegeri
    pungens, see Linanthus pungens
Leptosiphon
    bicolor (True babystars)
    breviculus (Mojave linanthus)
    chrysanthus ssp. chrysanthus (Golden gilia)
    chrysanthus ssp. decorus (Cream gilia)
    ciliatus (Whiskerbrush)
    floribundus ssp. floribundus (Many-flowered linanthus)
    floribundus ssp. glaber (Smooth many-flowered linanthus)
    floribundus ssp. hallii (Santa Rosa Mountains linanthus)
    grandiflorus (Large-flowered leptosiphon)
    lemmonii (Lemmon's linanthus)
    liniflorus (Flax-flowered linanthus)
    parviflorus (Common linanthus)
    pygmaeus ssp. continentalis (Pygmy linanthus)
Leptosyne
    bigelovii (Bigelow's coreopsis)
    californica (California tickseed)
    calliopsidea (Leafstem tickseed)
    gigantea (Giant coreopsis)
    maritima (Sea Dahlia)
Lesquerella
    kingii ssp. bernardina, see Physaria kingii ssp. bernardina
    kingii ssp. kingii, see Physaria kingii ssp. kingii
    tenella, see Physaria tenella
Lessingia
    filaginifolia var. filaginifolia, see Corethrogyne filaginifolia
    glandulifera var. glandulifera (Sticky lessingia)
    glandulifera var. tomentosa (Warner Springs lessingia)
    lemmonii var. lemmonii, see Lessingia glandulifera var. glandulifera
    tenuis (Spring lessingia)
Leucanthemum vulgare (Ox-eye daisy)*
Leucosyris arida (Silver Lake daisy)
Lewisia
    nevadensis (Sierra lewisia)
    pygmaea (Dwarf lewisia)
    rediviva var. minor (Bitterroot)
Leymus
    cinereus, see Elymus cinereus
    condensatus, see Elymus condensatus
    pacificus, see Elymus pacificus
Lilaea scilloides, see Triglochin scilloides
Lilium
    humboldtii ssp. ocellatum (Humboldt lily)
    pardalinum (Leopard lily)
    parryi (Lemon lily)
Limnanthes
    alba ssp. parishii (Parish's meadowfoam)
    gracilis ssp. parishii, see Limnanthes alba ssp. parishii
Limonium
    californicum (Sea-lavender)
    sinuatum (Statice)*
Limosella acaulis (Stemless mudwort)
Linanthus
    aureus ssp. aureus, see Leptosiphon aureus ssp. aureus
    aureus ssp. decorus, see Leptosiphon aureus ssp. decorus
    bellus (Desert beauty)
    bigelovii ssp. johnsonii (Bigelow's linanthus)
    breviculus, see Leptosiphon breviculus
    californicus (Prickly phlox)
    campanulatus (Bell gilia)
    ciliatus, see Leptosiphon ciliatus
    concinnus (San Gabriel linanthus)
    demissus (Desert linanthus)
    dianthiflorus (Ground pink)
    dichotomus (Evening snow)
    filiformis (Threadstem gilia)
    floribundus ssp. glaber, see Leptosiphon floribundus ssp. glaber
    floribundus ssp. hallii, see Leptosiphon floribundus ssp. hallii
    floribundus ssp. floribundus, see Leptosiphon floribundus ssp. floribundus
    jaegeri (San Jacinto prickly phlox)
    jonesii (Jones' linanthus)
    killipii (Baldwin Lake linanthus)
    liniflorus, see Leptosiphon liniflorus
    maculatus ssp. maculatus (Little San Bernardino Mountains linanthus)
    parryae (Parry's linanthus)
    parviflorus, see Leptosiphon parviflorus
    pungens (Mountain prickly phlox)
    pygmaeus ssp. continentalis, see Leptosiphon pygmaeus ssp. continentalis
Linaria
    canadensis var. texana, see Nuttallanthus texanus
    dalmatica ssp. dalmatica (Dalmatian toadflax)*
Linum
    lewisii var. lewisii (Western blue flax)
    puberulum (Plains flax)
    usitatissimum (Common flax)*
Listera convallarioides (Twayblade)
Lithocarpus densiflorus var. densiflorus, see Notholithocarpus densiflorus var. densiflorus
Lithophragma
    affine (Woodland star)
    bolanderi (Bolander's woodland star)
    cymbalaria (Mission woodland star)
    heterophyllum (Hillside woodland star)
    parviflorum var. parviflorum (Smallflower woodland star)
    tenellum (Slender woodland star)
Lithospermum incisum (Narrowleaf stoneseed)
Lobelia
    cardinalis var. pseudosplendens (Scarlet lobelia)
    dunnii var. serrata (Dunn's lobelia)
Lobularia maritima (Sweet alyssum)*
Loeflingia squarrosa (Spreading pygmyleaf)
Loeseliastrum
    matthewsii (Desert calico)
    schottii (Schott's calico)
Logfia
    arizonica (Arizona herba impia)
    depressa (Dwarf filago)
    filaginoides (California filago)
    gallica (Narrow-leaf filago)*
Lolium
    multiflorum, see Festuca perennis
    temulentum, see Festuca temulenta
Lomatium
    californicum (California lomatium)
    caruifolium var. caruifolium (Caraway-leaved lomatium)
    dasycarpum ssp. dasycarpum (Woolly lomatium)
    lucidum (Shiny lomatium)
    mohavense (Desert parsley)
    multifidum (Fernleaf lomatium)
    nevadense var. nevadense (Nevada lomatium)
    nevadense var. parishii (Parish's lomatium)
    parryi (Parry's wild parsley)
    utriculatum (Hog fennel)
Lonicera
    hispidula (Hairy honeysuckle)
    interrupta (Chaparral honeysuckle)
    involucrata var. ledebourii (Twinberry)
    subspicata var. denudata (Southern honeysuckle)
Lotus  
    argophyllus var. adsurgens, see Acmispon argophyllus var. adsurgens
    argophyllus var. argophyllus, see Acmispon argophyllus var. argophyllus
    argophyllus var. niveus, see Acmispon argophyllus var. niveus
    argyraeus var. argyraeus, see Acmispon argyraeus var. argyraeus
    argyraeus var. multicaulis, see Acmispon argyraeus var. multicaulis
    corniculatus (Bird's-foot trefoil)*
    crassifolius var. crassifolius, see Hosackia crassifolia var. crassifolia
    dendroideus var. dendroideus, see Acmispon dendroideus var. dendroideus
    dendroideus var. veatchii, see Acmispon dendroideus var. veatchii
    denticulatus, see Acmispon denticulatus
    grandiflorus var. grandiflorus, see Acmispon grandiflorus var. grandiflorus
    hamatus, see Acmispon micranthus
    heermannii var. heermannii, see Acmispon heermannii var. heermannii
    humistratus, see Acmispon brachycarpus
    nevadensis var. davidsonii, see Acmispon nevadensis var. davidsonii
    nevadensis var. nevadensis, see Acmispon nevadensis var. nevadensis
    oblongifolius var. oblongifolius, see Hosackia oblongifolia var. oblongifolia
    procumbens var. procumbens, see Acmispon procumbens var. procumbens
    purshianus var. purshianus, see Acmispon americanus var. americanus
    rigidus, see Acmispon rigidus
    salsuginosus var. brevivexillus, see Acmispon maritimus var. brevivexillus
    salsuginosus var. salsuginosus, see Acmispon maritimus var. maritimus
    scoparius var. brevialatus, see Acmispon glaber var. brevialatus
    scoparius var. scoparius, see Acmispon glaber var. glaber
    strigosus, see Acmispon strigosus
    wrangelianus, see Acmispon wrangelianus
Ludwigia peploides (Yellow water-weed)*
Lunaria annua (Annual moonwort)*
Lupinus
    adsurgens (Drew's silky lupine)
    albifrons var. albifrons (Silver bush lupine)
    albifrons var. austromontanus (Southern mountain lupine)
    albifrons var. douglasii (Douglas's silver bush lupine)
    albifrons var. hallii (Hall's bush lupine)
    albifrons var. johnstonii (Johnston's bush lupine)
    andersonii (Anderson's lupine)
    arboreus (Coast bush lupine)
    arbustus (Long-spurred lupine)
    argenteus var. argenteus (Silvery lupine)
    arizonicus (Arizona lupine)
    benthamii (Bentham lupine)
    bicolor (Miniature lupine)
    brevicaulis (Sand lupine)
    breweri var. breweri (Brewer's lupine)
    breweri var. bryoides (Matted lupine)
    breweri var. grandiflorus (Showy Brewer's lupine)
    chamissonis (Dune lupine)
    concinnus (Bajada lupine)
    elatus (Silky lupine)
    excubitus var. excubitus (Grape soda lupine)
    flavoculatus (Yellow-eyed lupine)
    formosus var. formosus (Summer lupine)
    hirsutissimus (Stinging lupine)
    hyacinthinus (San Jacinto lupine)
    latifolius var. latifolius (Broad-leaved lupine)
    latifolius var. parishii (Parish's lupine)
    lepidus var. confertus (Clustered tidy lupine)
    longifolius (Bush lupine)
    luteolus (Pale yellow lupine)
    luteus (European yellow lupine)*
    microcarpus var. densiflorus (White-whorled lupine)
    microcarpus var. horizontalis (Chick lupine)
    microcarpus var. microcarpus (Valley lupine)
    nanus (Sky lupine)
    odoratus (Royal desert lupine)
    peirsonii (Peirson's lupine)
    polyphyllus var. burkei (Meadow lupine)
    shockleyi (Desert lupine)
    sparsiflorus (Coulter's lupine)
    stiversii (Harlequin lupine)
    succulentus (Arroyo lupine)
    truncatus (Collar lupine)
Luzula comosa (Hairy wood rush)
Lycium
    andersonii (Anderson's thornbush)
    brevipes var. brevipes (Desert thorn)
    californicum (California boxthorn)
    cooperi (Cooper's boxthorn)
    fremontii (Fremont's thornbush)
    pallidum var. oligospermum (Rabbit thorn)
Lycopersicon esculentum (Common tomato)*
Lyonothamnus
    floribundus ssp. aspleniifolius (Fernleaf ironwood)
    floribundus ssp. floribundus (Santa Catalina Island ironwood)
Lyrocarpa coulteri (Coulter's lyrepod)
Lysimachia
    arvensis (Scarlet pimpernel)*
    minima (Common chaffweed)
Lythrum
    californicum (California loosestrife)
    hyssopifolia (Hyssop loosestrife)
Machaeranthera
    arida, see Arida arizonica
    asteroides var. asteroides, see Dieteria asteroides var. asteroides
    asteroides var. lagunensis, see Dieteria asteroides var. lagunensis
    canescens var. canescens, see Dieteria canescens var. canescens
    canescens var. leucanthemifolia, see Dieteria canescens var. leucanthemifolia
    canescens var. ziegleri, see Dieteria canescens var. ziegleri
    gracilis, see Xanthisma gracile
Madia
    elegans (Common madia)
    exigua (Threadstem madia)
    glomerata (Mountain madia)
    gracilis (Sticky madia)
    minima, see Hemizonella minima
Maianthemum
    racemosum (False solomon's seal)
    stellatum (Star-flowered false solomon's seal)
Malacothamnus
    clementinus (San Clemente Island bush mallow)
    davidsonii (Davidson's bush mallow)
    densiflorus (Many-flowered bush mallow)
    enigmaticus (Enigmatic bush mallow)
    fasciculatus var. fasciculatus (Bush mallow)
    fasciculatus var. nesioticus (Santa Cruz Island bush mallow)
    fremontii (Fremont's bush mallow)
    orbiculatus (Round-leaved bush mallow)
Malacothrix
    californica (California malacothrix)
    clevelandii (Annual malacothrix)
    coulteri (Snake's head)
    glabrata (Desert dandelion)
    incana (Dunedelion)
    saxatilis var. implicata (Cliff malacothrix)
    saxatilis var. tenuifolia (Short-leaved cliff-aster)
    sonchoides (Yellow saucers)
Malephora crocea (Red iceplant)*
Malosma laurina (Laurel sumac)
Malperia tenuis (Brown turbans)
Malva
    assurgentiflora (Island mallow)
    neglecta (Common mallow)*
    nicaeensis (Bull mallow)*
    parviflora (Cheeseweed)*
    pseudolavatera (Cretan mallow)*
Malvella leprosa (Alkali mallow)
Mammillaria
    dioica (Strawberry cactus)
    tetrancistra (Fishhook cactus)
Marah
    fabacea (California man-root)
    horrida (Sierra man-root)
    macrocarpa (Wild cucumber)
Marina
    orcuttii var. orcuttii (California marina)
    parryi (Parry's marina)
Marrubium vulgare (Horehound)*
Marsilea vestita ssp. vestita (Clover fern)
Matelea parvifolia (Desert spearleaf)
Matricaria
    discoidea (Pineapple weed)*
    matricarioides, see Matricaria discoidea
    occidentalis (Valley mayweed)
Matthiola incana (Garden stock)*
Maurandella antirrhiniflora (Violet twining snapdragon)
Maurandya antirrhiniflora ssp. antirrhiniflora, see Maurandella antirrhiniflora
Meconella denticulata (Small-flowered meconella)
Medicago
    lupulina (Black medick)*
    polymorpha (California bur-clover)*
    sativa (Alfalfa)*
Melica
    frutescens (Tall melica)
    imperfecta (Coast range melic)
    stricta (Rock melic)
Melilotus
    albus (White sweetclover)*
    indicus (Sourclover)*
    officinalis (Yellow sweetclover)*
Menodora
    scabra (Rough menodora)
    spinescens (Spiny menodora)
Mentha
    arvensis (Field mint)*
    Xpiperita (Bergamot mint)*
    spicata (Spearmint)*
Mentzelia
    affinis (Yellow comet)
    albicaulis (Whitestem blazing star)
    congesta (Clustered blazing star)
    dispersa (Bushy blazing star)
    hirsutissima (Hairy blazing star)
    involucrata (Sand blazing star)
    jonesii (Jones' blazing star)
    laevicaulis (Giant blazing star)
    lindleyi (Lindley's blazing star)
    longiloba (Yerba amarilla)
    micrantha (Stickleaf)
    montana (Mountain blazing star)
    multiflora var. longiloba, see Mentzelia longiloba
    obscura (Pacific blazing star)
    oreophila (Inyo blazing star)
    polita (Polished blazing star)
    reflexa (Reflexed blazing star)
    veatchiana (Veatch's blazing star)
Mesembryanthemum
    crystallinum (Crystalline iceplant)*
    nodiflorum (Slender-leaved iceplant)*
Micranthes californica (California saxifrage)
Micropus californicus var. californicus (Slender cottonweed)
Microseris douglasii ssp. douglasii (Douglas's microseris)
Microsteris gracilis (Slender phlox)
Mimetanthe pilosa (Downy monkeyflower)
Mimulus
    androsaceus, see Erythranthe androsaceus
    aridus, see Diplacus aridus
    aurantiacus var. puniceus, see Diplacus puniceus
    bigelovii var. bigelovii, see Diplacus bigelovii var. bigelovii
    bigelovii var. cuspidatus, see Diplacus bigelovii var. cuspidatus
    bolanderi, see Diplacus bolanderi
    brevipes, see Diplacus brevipes
    breweri, Erythranthe breweri
    cardinalis, see Erythranthe cardinalis
    clevelandii, see Diplacus clevelandii
    congdonii, see Diplacus congdonii
    constrictus, see Diplacus constrictus
    exiguus, see Erythranthe exigua
    flemingii, see Diplacus parviflorus
    floribundus, see Erythranthe floribunda
    fremontii, see Diplacus fremontii
    geniculatus, see Erythranthe geniculata
    guttatus, see Erythranthe guttata
    inconspicuus, see Erythranthe inconspicua
    johnstonii, see Diplacus johnstonii
    longiflorus, see Diplacus longiflorus
    longiflorus ssp. calycinus, see Diplacus calycinus
    moschatus, see Erythrina inodora
    palmeri, see Erythranthe palmeri
    parishii, see Erythranthe parishii
    pictus, see Diplacus pictus
    pilosa, Mimetanthe pilosa
    primuloides, see Diplacus primuloides
    purpureus, see Erythranthe purpurea
    rubellus, see Erythranthe rubella
    rupicola, see Diplacus rupicola
    shevockii, see Erythranthe shevockii
    suksdorfii, see Erythranthe suksdorfii
    tilingii, see Erythranthe tilingii
Mirabilis
    albida (Dwarf four o'clock)
    bigelovii var. bigelovii, see Mirabilis laevis var. villosa
    bigelovii var. retrorsa, see Mirabilis laevis var. retrorsa
    coccinea (Red four o'clock)
    jalapa var. jalapa (Cultivated four o'clock)*
    laevis var. crassifolia (Wishbone bush)
    laevis var. retrorsa (Retrorse desert four o'clock)
    laevis var. villosa (Desert wishbone bush)
    multiflora var. pubescens (Giant four o'clock)
    pumila, see Mirabilis albida
    tenuiloba (Slender-lobed four o'clock)
Mohavea
    breviflora, see Antirrhinum mohavea
    confertiflora, see Antirrhinum confertiflorum
Mollugo cerviana (Threadstem carpet-weed)*
Monanthochloe littoralis, see Distichlis littoralis
Monarda pectinata (Bee balm)
Monardella
    australis ssp. australis (Southern monardella)
    australis ssp. cinerea (Gray monardella)
    breweri ssp. breweri (Brewer's monardella)
    breweri ssp. lanceolata (Mustang mint)
    exilis (Desert pennyroyal)
    hypoleuca ssp. hypoleuca (White-leaf monardella)
    lanceolata, see Monardella breweri ssp. lanceolata
    linoides ssp. erecta (Narrow-leaved monardella)
    linoides ssp. linoides (Flax-leaved monardella)
    linoides ssp. oblonga (Tehachapi monardella)
    linoides ssp. viminea, see Monardella viminea
    macrantha ssp. hallii (Red monardella)
    nana (Little monardella)
    robisonii (Rock pennyroyal)
    viminea (Willowy monardella)
Monolepis nuttalliana (Nuttall's poverty weed)
Monolopia
    lanceolata (Common hillside daisy)
    stricta (Crum's monolopia)
Monoptilon
    bellidiforme (Daisy desertstar)
    bellioides (Desert star)
Montia
    chamissoi (Toad lily)
    fontana (Water chickweed)
Morella californica (California wax-myrtle)
Mortonia utahensis (Mortonia)
Mucronea californica (California spineflower)
Muhlenbergia
    filiformis (Pullup muhly)
    porteri (Bush muhly)
    richardsonis (Mat muhly)
    rigens (Deergrass)
Muilla
    clevelandii, see Bloomeria clevelandii
    coronata (Pink funnel lily)
    maritima (Common muilla)
Munzothamnus blairii (Blair's munzothamnus)
Myosurus
    apetalus var. montanus (Bristly mousetail)
    cupulatus (Desert mousetail)
Myrica californica, see Morella californica
Myriophyllum sibiricum (Siberian water-milfoil)
Myriopteris
    clevelandii (Cleveland's lip fern)
    cooperae (Cooper's lip fern)
    covillei (Coville's lip fern)
    gracilis (Slender lip fern)
    newberryi (Cotton fern)
    parryi (Parry's lip fern)
    viscida (Viscid lip fern)
    wootonii (Wooton's lip fern)
Nama
    californicum (California fiddleleaf)
    demissa var. covillei (Coville's purple mat)
    demissa var. demissa (Purple mat)
    pusilla (Small-leaved nama)
    rothrockii (Rothrock's nama)
    stenocarpa (Mud nama)
Nassella
    cernua, see Stipa cernua
    lepida, see Stipa lepida
    pulchra, see Stipa pulchra
Nasturtium officinale (Watercress)
Navarretia
    atractyloides (Hollyleaf navarretia)
    breweri (Brewer's navarretia)
    capillaris (Miniature gilia)
    fossalis (Spreading navarretia)
    hamata ssp. hamata (Hooked navarretia)
    leptalea ssp. bicolor (Bridges' gilia)
    ojaiensis (Ojai navarretia)
    peninsularis (Baja navarretia)
    prostrata (Prostrate navarretia)
Nemacladus
    eastwoodiae (Eastwood's threadplant)
    glanduliferus (Glandular threadplant)
    glanduliferus var. glanduliferus, see Nemacladus glanduliferus
    glanduliferus var. orientalis, see Nemacladus orientalis
    longiflorus var. breviflorus (Desert short-flowered threadplant)
    longiflorus var. longiflorus (Long-flowered threadplant)
    orientalis (Eastern threadplant)
    parikhiae (Parikh's threadplant)
    pinnatifidus (Comb-leaved threadplant)
    ramosissimus (Smallflower threadplant)
    rubescens (Desert threadplant)
    sigmoideus (Sigmoid threadplant)
    tenuis var. tenuis (Slender threadplant)
    twisselmannii var. botanywomaniae (Botany woman's threadplant)
Nemophila
    maculata (Fivespot)
    menziesii var. integrifolia (Large-flower baby blue eyes)
    menziesii var. menziesii (Small-flower baby blue eyes)
    pedunculata (Meadow nemophila)
    pulchella var. pulchella (Eastwood's baby blue eyes)
    spatulata (Sierra nemophila)
Nepeta cataria (Catnip)*
Nerium oleander (Common oleander)*
Nicolletia occidentalis (Hole-in-the-sand plant)
Nicotiana
    attenuata (Coyote tobacco)
    glauca (Tree tobacco)*
    obtusifolia (Desert tobacco)
    quadrivalvis (Four-valved tobacco)
Nitrophila mohavensis (Amargosa nitrophila)
Nolina
    bigelovii (Beargrass)
    cismontana (Chaparral beargrass)
    interrata (Dehesa nolina)
    parryi (Parry's nolina)
Notholaena californica (California cloak fern)
Notholithocarpus densiflorus var. densiflorus (Tanbark oak)
Nuttallanthus texanus (Blue toadflax)
Oemleria cerasiformis (Oso berry)
Oenanthe sarmentosa (Water-parsley)
Oenothera
    avita ssp. eurekensis (Eureka Dunes evening primrose)
    californica ssp. avita (Desert evening primrose)
    californica ssp. californica (California evening primrose)
    cavernae (Cave evening primrose)
    cespitosa ssp. marginata (Tufted evening primrose)
    deltoides ssp. deltoides (Basket evening primrose)
    elata ssp. hirsutissima (Hairy evening primrose)
    elata ssp. hookeri (Hooker's evening primrose)
    primiveris (Large yellow primrose)
    rosea (Rose evening primrose)*
    sinuosa (Wavyleaf bee blossom)*
    suffrutescens (Scarlet gaura)
Oligomeris linifolia (Oligomeris)
Olneya tesota (Desert ironwood)
Oncosiphon piluliferum (Globe chamomile)*
Ophioglossum californicum (California adder's-tongue)
Opuntia
    acanthocarpa var. coloradensis, see Cylindropuntia acanthocarpa var. coloradensis
    basilaris var. basilaris (Beavertail cactus)
    basilaris var. brachyclada (Short-joint beavertail cactus)
    basilaris var. treleasei (Bakersfield cactus)
    bigelovii, see Cylindropuntia bigelovii
    chlorotica (Pancake prickly-pear)
    echinocarpa, see Cylindropuntia echinocarpa
    erinacea var. erinacea, see Opuntia polyacantha var. erinacea
    ficus-indica (Mission cactus)*
    fosburgii, see Cylindropuntia fosburgii
    littoralis (Coast prickly-pear)
    oricola (Chaparral prickly-pear)
    parishii, see Grusonia parishii
    parryi var. parryi, see Cylindropuntia californica var. parkeri
    phaeacantha (Desert prickly-pear)
    polyacantha var. erinacea (Mojave prickly-pear)
    prolifera, see Cylindropuntia prolifera
    ramosissima, see Cylindropuntia ramosissima
    vaseyi (Vasey's prickly-pear)
    wolfii, see Cylindropuntia wolfii
Oreocarya
    abortiva (Bownut cryptantha)
    confertiflora (Yellow cryptantha)
    flavoculata (Roughseed cryptantha)
    tumulosa (New York Mountains cryptantha)
    virginensis (Virgin River cryptantha)
Oreonana vestita (Woolly mountain parsley)
Oreostemma alpigenum var. andersonii (Alpine aster)
Ornithostaphylos oppositifolia (Baja birdbush)
Orobanche, see Aphyllon
Orthilia secunda (One-sided wintergreen)
Osmadenia tenella (Three-spot)
Osmorhiza
    berteroi (Mountain sweet-cicely)
    brachypoda (Common sweet-cicely)
    chilensis, see Osmorhiza berteroi
Osteospermum ecklonis, see Dimorphotheca ecklonis
Oxalis
    albicans ssp. californica, see Oxalis californica
    albicans ssp. pilosa, see Oxalis pilosa
    californica (California oxalis)
    corniculata (Creeping wood-sorrel)*
    pes-caprae (Bermuda buttercup)*
    pilosa (Wild oxalis)
Oxypolis occidentalis (Western cowbane)
Oxytheca
    caryophylloides, see Sidotheca caryophylloides
    emarginata, see Sidotheca emarginata
    parishii var. cienegensis, see Acanthoscyphus parishii var. cienegensis
    parishii var. goodmaniana, see Acanthoscyphus parishii var. goodmaniana
    parishii var. parishii, see Acanthoscyphus parishii var. parishii
    perfoliata (Roundleaf oxytheca)
    trilobata, see Sidotheca trilobata
Oxytropis oreophila var. oreophila (Mountain oxytrope)
Packera
    bernardina (San Bernardino ragwort)
    ionophylla (Tehachapi ragwort)
    multilobata (Basin butterweed)
Paeonia californica (Wild peony)
Palafoxia
    arida var. arida (Spanish needles)
    arida var. gigantea (Giant Spanish needles)
Panicum urvilleanum (Desert panic grass)
Papaver
    californicum (Fire poppy)
    heterophyllum (Wind poppy)
Parapholis incurva (Curved sicklegrass)*
Paraserianthes lophantha (Plume acacia)*
Parietaria
    hespera var. hespera (Pellitory)
    pensylvanica (Pennsylvania pellitory)
Parkinsonia
    florida (Palo verde)
    microphylla (Littleleaf palo verde)
Parnassia
    californica, see Parnassia palustris
    palustris (Grass-of-parnassus)
Parthenium argentatum (Guayule)*
Paspalum
    dilatatum (Dallis grass)*
    distichum (Knot grass)
Pectis papposa var. papposa (Golden chinch flower)
Pectocarya
    heterocarpa (Hairy-leaved pectocarya)
    linearis ssp. ferocula (Slender pectocarya)
    penicillata (Winged pectocarya)
    platycarpa (Broad-fruited pectocarya)
    recurvata (Curvenut pectocarya)
    setosa (Bristly pectocarya)
Pedicularis
    attollens (Little elephant heads)
    densiflora (Warrior's plume)
    semibarbata (Pine lousewort)
Pediomelum californicum (California breadroot)
Pelazoneuron puberulum var. sonorensis (Sonoran maiden fern)
Pellaea
    andromedifolia (Coffee fern)
    breweri (Brewer's cliffbrake)
    mucronata var. californica (California cliff brake)
    mucronata var. mucronata (Bird's-foot fern)
    truncata (Cliff brake)
Pennisetum
    clandestinum (Kikuyu grass)*
    setaceum (Fountaingrass)*
Penstemon
    caesius (San Bernardino beardtongue)
    calcareus (Limestone beardtongue)
    californicus (California beardtongue)
    centranthifolius (Scarlet bugler)
    clevelandii var. clevelandii (Cleveland's beardtongue)
    clevelandii var. connatus (San Jacinto beardtongue)
    clevelandii var. mohavensis (Mojave beardtongue)
    Xdubius (Doubtful penstemon)
    eatonii var. undosus (Firecracker penstemon)
    floridus var. austinii (Austin's beardtongue)
    fruticiformis var. fruticiformis (Desert beardtongue)
    grinnellii var. grinnellii (Grinnell's penstemon)
    grinnellii var. scrophularioides (Northern Grinnell's penstemon)
    heterophyllus var. australis (Southern foothill penstemon)
    heterophyllus var. heterophyllus (Foothill penstemon)
    labrosus (San Gabriel beardtongue)
    laetus var. laetus (Mountain blue penstemon)
    newberryi var. newberryi (Pride of the mountains)
    palmeri var. palmeri (Palmer's penstemon)
    pseudospectabilis (Desert penstemon)
    rostriflorus (Beaked penstemon)
    speciosus (Royal penstemon)
    spectabilis var. spectabilis (Smooth showy penstemon)
    spectabilis var. subviscosus (Glandular showy penstemon)
    stephensii (Stephens' beardtongue)
    thompsoniae (Thompson's beardtongue)
    thurberi (Thurber's penstemon)
    utahensis (Utah penstemon)
Pentachaeta
    aurea ssp. allenii (Allen's daisy)
    aurea ssp. aurea (Golden-rayed pentachaeta)
    lyonii (Lyon's pentachaeta)
Pentagramma
    maxonii (Maxon's goldback fern)
    rebmanii (Rebman's silverback fern)
    triangularis ssp. triangularis (Goldback fern)
    viscosa (Coastal silverback fern)
Pericome caudata (Mountain tail leaf)
Perideridia
    parishii ssp. latifolia (Wide-leaved Parish's yampah)
    parishii ssp. parishii (Parish's yampah)
    pringlei (Adobe yampah)
Perityle emoryi (Rock daisy)
Persicaria
    amphibia (Swamp knotweed)
    capitata (Himalayan smartweed)*
    hydropiper (Water pepper)
    lapathifolia (Willow smartweed)
    punctata (Water smartweed)
Petalonyx
    nitidus (Shinyleaf sandpaper plant)
    thurberi ssp. thurberi (Sandpaper plant)
Petrophytum caespitosum ssp. caespitosum (Rock spiraea)
Petrorhagia dubia (Hairypink)*
Petunia parviflora (Wild petunia)
Peucephyllum schottii (Desert-fir)
Phacelia
    affinis (Limestone phacelia)
    anelsonii (Aven Nelson's phacelia)
    austromontana (Southern mountain phacelia)
    bicolor (Two-color phacelia)
    brachyloba (Yellow-throated phacelia)
    calthifolia (Caltha-leaved phacelia)
    campanularia var. campanularia (Desert bluebells)
    campanularia var. vasiformis (Funnel bluebells)
    cicutaria var. cicutaria (White caterpillar phacelia)
    cicutaria var. hispida (Caterpillar phacelia)
    cicutaria var. hubbyi, see Phacelia hubbyi
    ciliata (Great valley phacelia)
    congdonii (Congdon's phacelia)
    crenulata var. ambigua (Notch-leaf phacelia)
    crenulata var. crenulata (Cleftleaf wild heliotrope)
    crenulata var. minutiflora (Smallflower notchleaf phacelia)
    cryptantha (Hiddenflower phacelia)
    curvipes (Curved-stem phacelia)
    davidsonii (Davidson's phacelia)
    distans (Common phacelia)
    douglasii (Douglas phacelia)
    egena (Rock phacelia)
    exilis (Lavender windows)
    fremontii (Fremont's phacelia)
    grandiflora (Large-flowered phacelia)
    hastata var. hastata (Timberline phacelia)
    hubbyi (Hubby's phacelia)
    humilis var. dudleyi (Low phacelia)
    imbricata var. imbricata (Mountain phacelia)
    imbricata var. patula (Imbricate phacelia)
    insularis var. insularis (Northern Channel Islands phacelia)
    ivesiana (Ives' phacelia)
    lemmonii (Lemmon's phacelia)
    longipes (Longstalk phacelia)
    minor (Canterbury bells)
    mohavensis (Mojave phacelia)
    mutabilis (Changeable phacelia)
    nashiana (Charlotte's phacelia)
    neglecta (Alkali phacelia)
    pachyphylla (Thick-leaved phacelia)
    parryi (Parry's phacelia)
    pedicellata (Pedicellate phacelia)
    perityloides var. perityloides (Panamint phacelia)
    ramosissima (Branching phacelia)
    rotundifolia (Round-leaved phacelia)
    tanacetifolia (Tansy-leaved phacelia)
    vallis-mortae (Death Valley phacelia)
    viscida var. albiflora (White sticky phacelia)
    viscida var. viscida (Sticky phacelia)
Phalaris aquatica (Harding grass)*
Philadelphus microphyllus (Little-leaved mock orange)
Phleum alpinum (Mountain timothy)
Phlox
    austromontana (Southern mountain phlox)
    condensata (Condensed phlox)
    diffusa (Spreading phlox)
    dolichantha (Big Bear Valley phlox)
    gracilis, see Microsteris gracilis
    stansburyi ssp. stansburyi (Stansbury phlox)
Pholisma
    arenarium (Scaly-stemmed sand plant)
    sonorae (Sand food)
Pholistoma
    auritum var. auritum (Fiesta flower)
    membranaceum (White fiesta flower)
Phoradendron
    bolleanum (Bolle's mistletoe)
    californicum (Desert mistletoe)
    densum, see Phoradendron bolleanum
    juniperinum (Juniper mistletoe)
    leucarpum ssp. macrophyllum (Big-leaf mistletoe)
    leucarpum ssp. tomentosum (Oak mistletoe)
    libocedri, see Phoradendron juniperinum
    macrophyllum, see Phoradendron serotinum ssp. macrophyllum
    pauciflorum, see Phoradendron bolleanum
    serotinum ssp. macrophyllum, see P. leucarpum ssp. macrophyllum
    serotinum ssp. tomentosum, see P. leucarpum ssp. tomentosum
    villosum, see Phoradendron serotinum ssp. tomentosum
Phragmites australis (Common reed)
Phyllodoce breweri (Mountain heather)
Physalis
    crassifolia (Thick-leaved ground-cherry)
    hederifolia var. fendleri (Fendler's ground-cherry)
    lobata (Lobed ground-cherry)
Physaria
    kingii ssp. bernardina (San Bernardino Mountains bladderpod)
    kingii ssp. kingii (King's bladderpod)
    tenella (Palmer's beadpod)
Physocarpus
    alternans (Nevada ninebark)
    capitatus (Pacific ninebark)
Phytolacca americana (Pokeweed)*
Pickeringia
    montana var. montana (Chaparral pea)
    montana var. tomentosa (Woolly chaparral pea)
Picradeniopsis multiflora (Many-flowered bahia)
Picris echioides, see Helminthotheca echioides
Pilostyles thurberi (Thurber's stemsucker)
Pinus
    attenuata (Knobcone pine)
    contorta ssp. murrayana (Lodgepole pine)
    coulteri (Coulter pine)
    flexilis (Limber pine)
    halepensis (Aleppo pine)*
    jeffreyi (Jeffrey pine)
    lambertiana (Sugar pine)
    longaeva (Bristlecone pine)
    monophylla (Singleleaf pinyon pine)
    muricata (Bishop pine)
    ponderosa var. pacifica (Yellow pine)
    quadrifolia (Four-needle pinyon pine)
    sabiniana (Gray pine)
    torreyana ssp. insularis (Santa Rosa Island torrey pine)
    torreyana ssp. torreyana (Torrey pine)
Piperia
    cooperi (Rein orchid)
    elongata (Dense-flowered rein orchid)
    transversa (Royal rein orchid)
    unalascensis (Alaska rein orchid)
Piptatherum miliaceum, see Stipa miliacea
Plagiobothrys
    acanthocarpus (Adobe popcorn flower)
    arizonicus (Arizona popcorn flower)
    canescens var. canescens (Valley popcorn flower)
    collinus var. fulvescens (California popcorn flower)
    fulvus var. campestris (Tawny popcorn flower)
    hispidulus (Harsh popcorn flower)
    jonesii, see Simpsonanthus jonesii
    nothofulvus (Rusty-haired popcorn flower)
    tenellus (Slender popcorn flower)
    undulatus (Hooked popcorn flower)
Plantago
    arenaria (Sand plantain)*
    coronopus (Cut-leaf plantain)*
    elongata (Longleaf plantain)
    erecta (California plantain)
    lanceolata (English plantain)*
    major (Broad-leaf plantain)*
    ovata var. fastigiata (Woolly plantain)
    patagonica (Patagonia plantain)
Platanthera
    dilatata var. leucostachys (White-flowered bog orchid)
    leucostachys, see Platanthera dilatata var. leucostachys
    sparsiflora (Sparse-flowered bog orchid)
Platanus racemosa (Western sycamore)
Platystemon californicus (Cream cups)
Plectritis ciliosa (Long-spurred plectritis)
Pleiacanthus spinosus (Thorny skeleton-plant)
Pleuraphis rigida, see Hilaria rigida
Pleurocoronis pluriseta (Arrowleaf)
Pluchea
    odorata var. odorata (Salt marsh fleabane)
    sericea (Arrow-weed)
Poa
    atropurpurea (San Bernardino bluegrass)
    bulbosa ssp. vivipara (Bulbous bluegrass)*
    douglasii (Sand-dune bluegrass)
    fendleriana ssp. longiligula (Fendler's bluegrass)
    infirma (Weak bluegrass)*
    pratensis ssp. pratensis (Kentucky bluegrass)*
    secunda ssp. juncifolia (Rush bluegrass)
    secunda ssp. secunda (One-sided bluegrass)
Pogogyne nudiuscula (Otay Mesa mint)
Polemonium occidentale (Western sky pilot)
Polycarpon tetraphyllum ssp. tetraphyllum (Four-leaf allseed)*
Polygala, see Rhinotropis
Polygonum
    amphibium var. emersum, see Persicaria amphibia
    arenastrum, see Polygonum aviculare ssp. depressum
    aviculare ssp. depressum (Common knotweed)*
    bistortoides, see Bistorta bistortoides
    capitatum, see Persicaria capitata
    douglasii (Douglas's knotweed)
    douglasii ssp. johnstonii, see Polygonum sawatchense ssp. sawatchense
    lapathifolium, see Persicaria lapathifolia
    polygaloides ssp. kelloggii (Kellogg's knotweed)
    punctatum, see Persicaria punctata
    sawatchense ssp. sawatchense (Sawatch knotweed)
Polypodium
    californicum (California polypody)
    hesperium (Western polypody)
Polypogon
    interruptus (Ditch beard grass)*
    monspeliensis (Rabbitsfoot grass)*
    viridis (Green bentgrass)*
Polystichum
    imbricans ssp. curtum (Cliff sword fern)
    munitum (Western sword fern)
    scopulinum (Mountain holly fern)
Populus
    balsamifera ssp. trichocarpa, see Populus trichocarpa
    fremontii ssp. fremontii (Fremont's cottonwood)
    tremuloides (Quaking aspen)
    trichocarpa (Black cottonwood)
Porophyllum gracile (Slender poreleaf)
Portulaca
    halimoides (Desert portulaca)
    oleracea (Purslane)*
Potamogeton diversifolius (Diverse-leaved pondweed)
Potentilla
    anserina ssp. anserina (Common silverweed)
    anserina ssp. pacifica (Pacific silverweed)
    biennis (Biennial cinquefoil)
    glandulosa ssp. ewanii, see Drymocallis cuneifolia var. ewanii
    glandulosa ssp. glandulosa in part, see Drymocallis glandulosa var. glandulosa (TR, PR)
    glandulosa ssp. glandulosa in part, see Drymocallis glandulosa var. wrangelliana (SoCO)
    glandulosa ssp. nevadensis, see Drymocallis lactea var. lactea
    glandulosa ssp. reflexa in part, see Drymocallis glandulosa var. reflexa (TR,PR)
    glandulosa ssp. reflexa in part, see Drymocallis glandulosa var. viscida (TR,PR)
    gracilis var. fastigiata (Slender cinquefoil)
    norvegica (Norwegian cinquefoil)*
    wheeleri (Wheeler's cinquefoil)
Prenanthella exigua (Bright white)
Primula
    clevelandii var. clevelandii (Shooting star)
    clevelandii var. insularis (Island shooting star)
    fragrans (Fragrant shooting star)
    hendersonii (Foothill shooting star)
    tetrandra (Alpine shooting star)
Proboscidea althaeifolia (Desert unicorn-plant)
Prosopis
    glandulosa var. torreyana (Honey mesquite)
    pubescens (Screwbean mesquite)
Prunella vulgaris var. lanceolata (Self-heal)
Prunus
    andersonii (Desert peach)
    emarginata (Bitter cherry)
    eremophila (Mojave desert plum)
    fasciculata var. fasciculata (Desert almond)
    fremontii (Desert apricot)
    ilicifolia ssp. ilicifolia (Hollyleaf cherry)
    ilicifolia ssp. lyonii (Catalina cherry)
    virginiana var. demissus (Western chokecherry)
Psathyrotes
    annua (Fan leaf)
    ramosissima (Turtleback)
Pseudobahia peirsonii (San Joaquin adobe sunburst)
Pseudognaphalium
    beneolens (Fragrant everlasting)
    biolettii (Two-tone everlasting)
    californicum (California everlasting)
    canescens (Wright's cudweed)
    luteoalbum (Weedy cudweed)*
    microcephalum (Feltleaf everlasting)
    ramosissimum (Pink cudweed)
    stramineum (Cotton-batting plant)
    thermale (Slender everlasting)
Pseudotsuga macrocarpa (Big-cone douglas fir)
Psilocarphus
    brevissimus var. brevissimus (Dwarf woollyheads)
    tenellus (Slender woollyheads)
Psilostrophe cooperi (Paperflower)
Psorothamnus
    arborescens var. minutifolius (Little-leaved Mojave indigo bush)
    arborescens var. simplicifolius (California indigo bush)
    emoryi (Emory indigo bush)
    polydenius (Dotted indigo bush)
    schottii (Schott's indigo bush)
    spinosus (Smoke tree)
Ptelea crenulata (Hop tree)
Pteridium aquilinum var. pubescens (Bracken fern)
Pteris vittata (Ladder brake)*
Pterospora andromedea (Pinedrops)
Pterostegia drymarioides (Threadstem)
Pulicaria paludosa (Pulicaria)*
Purshia
    mexicana var. stansburyana, see Purshia stansburyana
    stansburyana (Cliff rose)
    tridentata var. glandulosa (Desert bitterbrush)
Pycnanthemum californicum (Mountain mint)
Pyrola
    asarifolia ssp. asarifolia (Bog wintergreen)
    dentata (Toothed wintergreen)
    minor (Lesser wintergreen)
    picta (White-veined wintergreen)
Pyrrocoma
    racemosa var. paniculata (Panicled pyrrocoma)
    uniflora var. gossypina (Bear Valley pyrrocoma)
Quercus
    acutidens (Torrey's scrub oak)
    agrifolia var. agrifolia (Coast live oak)
    agrifolia var. oxyadenia (Southern coast live oak)
    berberidifolia (Inland scrub oak)
    chrysolepis (Canyon live oak)
    cornelius-mulleri (Muller's oak)
    douglasii (Blue oak)
    dumosa (Coastal scrub oak)
    durata var. gabrielensis (San Gabriel Mountains leather oak)
    engelmannii (Engelmann oak)
    garryana var. breweri (Brewer's oak)
    john-tuckeri (Tucker's oak)
    kelloggii (California black oak)
    lobata (Valley oak)
    Xmorehus (Oracle oak)
    pacifica (Channel Island scrub oak)
    palmeri (Palmer's oak)
    tomentella (Island oak)
    turbinella (Shrub live oak)
    wislizeni var. frutescens (Shrubby interior live oak)
    wislizeni var. wislizeni (Interior live oak)
Rafinesquia
    californica (California chicory)
    neomexicana (Desert chicory)
Raillardella argentea (Silky raillardella)
Ranunculus
    alismifolius var. alismellus (Small water-plantain buttercup)
    aquatilis var. diffusus (Water buttercup)
    californicus var. californicus (California buttercup)
    cymbalaria (Alkali buttercup)
    eschscholtzii var. oxynotus (Eschscholtz's buttercup)
    hebecarpus (Delicate buttercup)
    occidentalis (Western buttercup)
    sceleratus (Cursed crowfoot)
    testiculatus (Tubercled crowfoot)*
Raphanus sativus (Wild radish)*
Rhamnus
    californica ssp. californica, see Frangula californica ssp. californica
    crocea (Littleleaf redberry)
    ilicifolia (Hollyleaf redberry)
    pirifolia (Island redberry)
    tomentella ssp. cuspidata, see Frangula californica ssp. cuspidata
    tomentella ssp. tomentella, see Frangula californica ssp. tomentella
Rhaponticum repens (Russian knapweed)*
Rhinotropis
    acanthoclada (Desert polygala)
    cornuta var. fishiae (Fish's milkwort)
Rhododendron occidentale (Western azalea)
Rhus
    aromatica (Skunkbrush)
    integrifolia (Lemonade berry)
    ovata (Sugar bush)
    trilobata, see Rhus aromatica
Ribes
    amarum (Bitter gooseberry)
    aureum var. gracillimum (Golden currant)
    californicum var. hesperium (Hillside gooseberry)
    cereum var. cereum (Wax currant)
    indecorum (White-flowering currant)
    malvaceum var. viridifolium (Chaparral currant)
    montigenum (Mountain gooseberry)
    nevadense (Mountain pink currant)
    quercetorum (Oak gooseberry)
    roezlii var. roezlii (Sierra gooseberry)
    speciosum (Fuchsia-flowered gooseberry)
    thacherianum (Santa Cruz Island gooseberry)
    velutinum (Desert gooseberry)
    viburnifolium (Evergreen currant)
Ricinus communis (Castor bean)*
Rigiopappus leptocladus (Wireweed)
Robinia
    neomexicana (Desert locust)
    pseudoacacia (Black locust)*
Romneya
    coulteri (Matilija poppy)
    trichocalyx (Bristly matilija poppy)
Rorippa
    curvipes (Bluntleaf yellowcress)
    curvisiliqua (Curvepod yellowcress)
    nasturtium-aquaticum, see Nasturtium officinale
    palustris ssp. palustris (Western bog yellowcress)
    sphaerocarpa (Round-fruit yellowcress)
Rosa
    californica (Wild rose)
    gymnocarpa var. gymnocarpa (Wood rose)
    minutifolia (Small-leaved rose)
    woodsii ssp. gratissima (Interior rose)
Rubus
    armeniacus (Himalaya-berry)*
    discolor, see Rubus armeniacus
    leucodermis (Western raspberry)
    parviflorus (Thimbleberry)
    ursinus (California blackberry)
Rumex
    acetosella (Sheep sorrel)*
    californicus (Willow-leaved dock)
    conglomeratus (Whorled dock)*
    crispus (Curly dock)*
    hymenosepalus (Wild-rhubarb)
    pulcher (Fiddle dock)*
    salicifolius var. denticulatus, see Rumex californicus
Rupertia
    physodes (California tea)
    rigida (Parish's psoralea)
Sabulina
    douglasii (Douglas's stitchwort)
    nuttallii var. gracilis (Brittle sandwort)
    pusilla (Annual sandwort)
Sagina
    apetala (Dwarf pearlwort)*
    decumbens ssp. occidentalis (Western pearlwort)
    saginoides (Alpine pearlwort)
Salazaria mexicana, see Scutellaria mexicana
Salicornia
    pacifica (Pacific pickleweed)
    subterminalis, see Arthrocnemum subterminale
    virginica, see Salicornia pacifica
Salix
    exigua var. exigua (Sandbar willow)
    exigua var. hindsiana (Hinds' narrowleaf willow)
    geyeriana (Geyer's willow)
    gooddingii (Goodding's black willow)
    laevigata (Red willow)
    lasiolepis (Arroyo willow)
    lemmonii (Lemmon's willow)
    lasiandra var. lasiandra (Shining willow)
    lucida ssp. lasiandra, see Salix lasiandra var. lasiandra
    scouleriana (Scouler's willow)
Salsola
    paulsenii (Barbwire Russian thistle)*
    tragus (Russian thistle)*
Saltugilia
    australis (Southern woodland-gilia)
    caruifolia (Caraway-leaved gilia)
    latimeri (Latimer's woodland-gilia)
    splendens ssp. grantii (Grant's woodland-gilia)
    splendens ssp. splendens (Splendid woodland-gilia)
Salvia
    apiana (White sage)
    brandegeei (Brandegee's sage)
    carduacea (Thistle sage)
    clevelandii (Cleveland's sage)
    columbariae (Chia)
    dorrii var. dorrii (Blue sage)
    dorrii var. pilosa (Hairy blue sage)
    eremostachya (Desert sage)
    funerea (Death Valley sage)
    leucophylla (Purple sage)
    mellifera (Black sage)
    munzii (Munz's sage)
    pachyphylla (Rose sage)
    sonomensis (Creeping sage)
    spathacea (Crimson pitcher sage)
    vaseyi (Vasey's sage)
Sambucus
    mexicana (Mexican elderberry)
    nigra ssp. caerulea, see Sambucus nigra ssp. caerulea
    racemosa var. racemosa (Red elderberry)
Samolus parviflorus (Water-pimpernel)
Sanicula
    arguta (Snakeroot)
    bipinnata (Poison sanicle)
    bipinnatifida (Purple sanicle)
    crassicaulis (Pacific sanicle)
    graveolens (Sierra sanicle)
    tuberosa (Turkey pea)
Sanvitalia abertii (Abert's sanvitalia)
Sarcodes sanguinea (Snow plant)
Sarcostemma
    cynanchoides ssp. hartwegii, see Funastrum cynanchoides var. hartwegii
    hirtellum, see Funastrum hirtellum
Satureja
    chandleri, see Clinopodium chandleri
    douglasii, see Clinopodium mimuloides
    mimuloides, see Clinopodium mimuloides
Saxifraga californica, see Micranthes californica
Schinus
    molle (Peruvian pepper)*
    terebinthifolius (Brazilian pepper)*
Schismus barbatus (Common Mediterranean grass)*
Schizotechium jamesianum (Sticky starwort)
Schkuhria multiflora var. multiflora, see Bahia neomexicana
Schoenoplectus
    americanus (American bulrush)
    californicus (California bulrush)
Schoenus nigricans (Black sedge)
Scirpus
    americanus, see Schoenoplectus americanus
    californicus, see Schoenoplectus californicus
    maritimus, see Bolboschoenus maritimus
    microcarpus (Panicled bulrush)
Sclerocactus
    johnsonii (Johnson's bee-hive cactus)
    polyancistrus (Mojave fishhook cactus)
Scopulophila rixfordii (Rixford's rockwort)
Scrophularia
    californica (California figwort)
    desertorum (Desert figwort)
Scutellaria
    bolanderi ssp. austromontana (Southern skullcap)
    mexicana (Paperbag bush)
    siphocampyloides (Grayleaf skullcap)
    tuberosa (Common skullcap)
Secale cereale (Cereal rye)*
Sedum
    niveum (Davidson's stonecrop)
    spathulifolium (Broad-leaf stonecrop)
Selaginella
    asprella (Bluish spike-moss)
    bigelovii (Bigelow's spike-moss)
    cinerascens (Ashy spike-moss)
    eremophila (Desert spike-moss)
    hansenii (Hansen's spike-moss)
    watsonii (Watson's spike-moss)
Senecio
    bernardinus, see Packera bernardina
    californicus (California groundsel)
    flaccidus var. douglasii (Bush senecio)
    flaccidus var. monoensis (Mono groundsel)
    fremontii var. occidentalis (Dwarf mountain ragwort)
    ionophyllus, see Packera ionophylla
    mohavensis (Mojave ragwort)
    multilobatus, see Packera multilobata
    spartioides (Broom groundsel)
    triangularis (Arrowleaf butterweed)
    vulgaris (Common groundsel)*
Senegalia greggii (Catclaw acacia)
Senna
    armata (Desert senna)
    artemisioides (Silver senna)*
    covesii (Coues' senna)
Sequoiadendron giganteum (Giant sequoia)*
Shepherdia argentea (Buffalo-berry)
Sherardia arvensis (Field madder)*
Sibbaldia procumbens (Sibbaldia)
Sidalcea
    malviflora ssp. dolosa (Dwarf checkerbloom)
    malviflora ssp. malviflora (Island checkerbloom)
    malviflora ssp. sparsifolia, see Sidalcea sparsifolia
    pedata (Big Bear checkerbloom)
    sparsifolia (Few-leaved checkerbloom)
Sidotheca
    caryophylloides (Chickweed oxytheca)
    emarginata (Whitemargin oxytheca)
    trilobata (Threelobe oxytheca)
Silene
    antirrhina (Sleepy catchfly)
    bernardina (Palmer's catchfly)
    gallica (Windmill pink)*
    krantzii (Krantz's catchfly)
    laciniata ssp. californica (California pink)
    laciniata ssp. laciniata (Mexican pink)
    laciniata ssp. major, see Silene laciniata ssp. laciniata
    lemmonii (Lemmon's catchfly)
    menziesii (Menzies' campion)
    multinervia (Many-nerved catchfly)
    parishii (Parish's catchfly)
    verecunda (White catchfly)
Silybum marianum (Milk thistle)*
Simmondsia chinensis (Jojoba)
Simpsonanthus jonesii (Mojave popcorn flower)
Sisymbrium
    altissimum (Tumble mustard)*
    irio (London rocket)*
    officinale (Hedge mustard)*
    orientale (Oriental mustard)*
Sisyrinchium
    bellum (Blue-eyed grass)
    elmeri (Yellow-eyed grass)
    funereum (Death Valley blue-eyed grass)
    halophilum (Nevada blue-eyed grass)
    idahoense var. occidentale (Idaho blue-eyed grass)
Smilacina
    racemosa, see Maianthemum racemosum
    stellata, see Maianthemum stellatum
Solanum
    americanum (Small-flowered nightshade)
    douglasii (White nightshade)
    elaeagnifolium (Silverleaf horse-nettle)*
    parishii (Parish's nightshade)
    umbelliferum (Blue-witch nightshade)
    xanti (Purple nightshade)
Solidago
    californica, see Solidago velutina ssp. californica
    confinis (Southern goldenrod)
    velutina ssp. californica (California goldenrod)
Sonchus
    asper ssp. asper (Prickly sow-thistle)*
    oleraceus (Sow-thistle)*
Spartina foliosa (Cord grass)
Spartium junceum (Spanish broom)*
Spergula arvensis (Corn spurrey)*
Spergularia
    bocconi (Boccone's sand-spurrey)*
    macrotheca var. macrotheca (Sticky sand-spurrey)
    marina (Salt marsh sand-spurrey)
    rubra (Red sand-spurrey)*
    villosa (Hairy sand-spurrey)*
Sphaeralcea
    ambigua var. ambigua (Apricot mallow)
    ambigua var. rosacea (Rosy apricot mallow)
    ambigua var. rugosa (Desert globemallow)
    angustifolia (Narrow-leaved globemallow)
    coulteri (Coulter's globemallow)
    rusbyi var. eremicola (Rusby's desert mallow)
Sphaeromeria cana (Gray chickensage)
Sphenosciadium capitellatum, see Angelica capitellata
Sporobolus airoides (Alkali sacaton)
Stachys
    albens (White hedge-nettle)
    bullata (California hedge-nettle)
    rigida (Rigid hedge-nettle)
Stanleya
    elata (Panamint prince's plume)
    pinnata var. pinnata (Prince's plume)
Stebbinsoseris heterocarpa (Brown microseris)
Stellaria
    calycantha (Northern starwort)
    longipes ssp. longipes (Meadow starwort)
    media (Chickweed)*
    nitens (Shining chickweed)
Stephanomeria
    cichoriacea (Chicory-leaved stephanomeria)
    diegensis (San Diego wreathplant)
    exigua ssp. coronaria (Whiteplume wirelettuce)
    exigua ssp. deanei (Deane's wirelettuce)
    exigua ssp. exigua (Small wirelettuce)
    parryi (Parry's wirelettuce)
    pauciflora (Desert straw)
    spinosa, see Pleiacanthus spinosus
    tenuifolia (Narrow-leaved stephanomeria)
    virgata ssp. pleurocarpa (Wand wirelettuce)
    virgata ssp. virgata (Twiggy wreathplant)
Stillingia
    linearifolia (Narrow-leaved stillingia)
    spinulosa (Broad-leaved stillingia)
Stipa
    arida (Mormon needlegrass)
    cernua (Nodding needlegrass)
    comata var. comata (Needle-and-thread)
    coronata (Giant stipa)
    diegoensis (San Diego County needlegrass)
    hymenoides (Sand ricegrass)
    lepida (Foothill needlegrass)
    miliacea var. miliacea (Smilo grass)*
    occidentalis var. occidentalis (Western needlegrass)
    parishii var. parishii (Parish's needlegrass)
    pulchra (Purple needlegrass)
    speciosa (Desert needlegrass)
Streptanthella longirostris (Longbeak streptanthella)
Streptanthus
    bernardinus (Laguna Mountains jewelflower)
    campestris (Southern jewelflower)
    cordatus var. cordatus (Heartleaf jewelflower)
Strigosella africana (African mustard)*
Stutzia covillei (Arrowscale)
Stylocline
    gnaphaloides (Everlasting neststraw)
    micropoides (Woollyhead neststraw)
Stylomecon heterophylla, see Papaver heterophyllum
Styrax
    officinalis var. redivivus, see Styrax redivivus
     redivivus (Snowdrop bush)
Suaeda
    esteroa (Estuary sea-blite)
    moquinii, see Suaeda nigra
    nigra (Rush seepweed)
    taxifolia (Woolly sea-blite)
Swallenia alexandrae (Eureka Valley dune grass)
Swertia
    neglecta, see Frasera neglecta
    parryi, see Frasera parryi
    puberulenta, see Frasera puberulenta
Symphoricarpos
    albus var. laevigatus (White snowberry)
    longiflorus (Fragrant snowberry)
    mollis (Creeping snowberry)
    rotundifolius var. parishii (Mountain snowberry)
Symphyotrichum
    ascendens (Long-leaved aster)
    chilense (Chile aster)
    defoliatum (San Bernardino aster)
    greatae (Greata's aster)
    lanceolatus ssp. hesperium (Western lanceleaf aster)
    spathulatum var. spathulatum (Western mountain aster)
    subulatum var. parviflorum (Slim aster)
Syntrichopappus fremontii (Fremont's syntrichopappus)
Tamarix
    aphylla (Athel)*
    parviflora (Small-flowered tamarisk)*
    ramosissima (Salt cedar)*
Tanacetum parthenium (Feverfew)*
Taraxacum
    californicum (California dandelion)
    officinale (Dandelion)*
Tauschia
    arguta (Southern tauschia)
    parishii (Parish's tauschia)
Tetracoccus
    dioicus (Parry's tetracoccus)
    hallii (Hall's tetracoccus)
    ilicifolius (Holly-leaved tetracoccus)
Tetradymia
    argyraea (Striped horsebrush)
    axillaris var. longispina (Longspine horsebrush)
    canescens (Spineless horsebrush)
    comosa (Cottonthorn)
    stenolepis (Mojave cottonthorn)
Tetragonia tetragonioides (New Zealand spinach)*
Tetraneuris acaulis var. arizonica (Arizona hymenoxys)
Tetrapteron palmeri (Palmer's sun cup)
Teucrium glandulosum (Desert germander)
Thalictrum
    fendleri var. fendleri (Fendler's meadow-rue)
    fendleri var. polycarpum (Meadow-rue)
    sparsiflorum (Few-flowered meadow-rue)
Thamnosma montana (Turpentine-broom)
Thelypodium
    integrifolium ssp. affine (Entire-leaved thelypodium)
    stenopetalum (Slender-petalled mustard)
Thelypteris puberula var. sonorensis, see Pelazoneuron puberulum var. sonorensis
Thermopsis
    californica var. argentata (Silvery false-lupine)
    californica var. semota (Velvety false-lupine)
    macrophylla var. argentata, see Thermopsis californica var. argentata
    macrophylla var. semota, see Thermopsis californica var. semota
Thymophylla pentachaeta var. belenidium (Five-needled thymophylla)
Thysanocarpus
    conchuliferus (Santa Cruz Island fringe-pod)
    curvipes (Fringe-pod)
    laciniatus (Lace-pod)
Tidestromia
    oblongifolia, see Tidestromia suffruticosa var. oblongifolia
    suffruticosa var. oblongifolia (Honeysweet)
Tiquilia
    canescens (Woody crinklemat)
    nuttallii (Nuttall's crinklemat)
    palmeri (Palmer's crinklemat)
    plicata (Fanleaf crinklemat)
Torilis
    arvensis (Field hedge-parsley)*
    nodosa (Hedge-parsley)*
Toxicodendron diversilobum (Western poison oak)
Toxicoscordion
    brevibracteatum (Desert zygadene)
    fremontii (Star lily)
    venenosum var. venenosum (Death camas)
Tragia ramosa (Noseburn)
Tragopogon
    dubius (Yellow salsify)*
     porrifolius (Purple salsify)*
Trianthema portulacastrum (Lowland purslane)
Tribulus terrestris (Puncture vine)*
Tricardia watsonii (Three-hearts)
Trichoptilium incisum (Yellowheads)
Trichostema
    austromontanum ssp. austromontanum (Southern bluecurls)
    austromontanum ssp. compactum (Hidden Lake bluecurls)
    lanatum (Woolly bluecurls)
    lanceolatum (Vinegar weed)
    micranthum (Smallflower bluecurls)
    parishii (Parish's bluecurls)
Tridens muticus (Slim tridens)
Trifolium
    albopurpureum (Rancheria clover)
    barbigerum (Bearded clover)
    ciliolatum (Foothill clover)
    depauperatum var. truncatum (Balloon clover)
    gracilentum (Pin-point clover)
    hirtum (Rose clover)*
    longipes var. nevadense, see Trifolium longipes ssp. hansenii
    longipes ssp. hansenii (Summer clover)
    microcephalum (Small-head field clover)
    monanthum ssp. grantianum (Grant's carpet clover)
    obtusiflorum (Creek clover)
    pratense (Red clover)*
    repens (White clover)*
    variegatum (Whitetip clover)
    willdenovii (Tomcat clover)
    wormskioldii (Mountain clover)
Triglochin scilloides (Flowering quillwort)
Triodanis biflora (Venus looking-glass)
Trisetum spicatum (Narrow oatgrass)
Triteleia
    ixioides ssp. scabra (Pretty face)
    laxa (Ithuriel's spear)
    lugens (Coast range triteleia)
Triticum aestivum (Common wheat)*
Trixis californica var. californica (California trixis)
Tropidocarpum gracile (Dobiepod)
Turricula parryi, see Eriodictyon parryi
Turritis glabra (Tower mustard)
Typha
    domingensis (Southern cattail)
    latifolia (Broad-leaved cattail)
Umbellularia californica (California bay)
Uropappus lindleyi (Silver puffs)
Urtica
    dioica ssp. holosericea (Hoary nettle)
    urens (Dwarf nettle)*
Vaccinium ovatum (California huckleberry)
Vachellia farnesiana var. farnesiana (Sweet acacia)*
Venegasia carpesioides (Canyon sunflower)
Veratrum californicum var. californicum (Corn lily)
Verbascum
    thapsus (Woolly mullein)*
    virgatum (Wand mullein)*
Verbena
    bracteata (Big-bract verbena)
    gooddingii (Goodding's verbena)
    lasiostachys var. lasiostachys (Western vervain)
    lasiostachys var. scabrida (Robust vervain)
    menthifolia (Mint-leaved vervain)
Verbesina
    dissita (Big-leaved crownbeard)
    encelioides ssp. exauriculata (Golden crownbeard)
Veronica
    americana (American speedwell)
    anagallis-aquatica (Water speedwell)*
    arvensis (Corn speedwell)*
    peregrina ssp. xalapensis (Purslane speedwell)
    persica (Persian speedwell)*
    serpyllifolia ssp. humifusa (Thyme-leaved speedwell)*
Vicia
    americana ssp. americana (American vetch)
    hassei (Slender vetch)
    ludoviciana ssp. ludoviciana (Slim vetch)
    sativa ssp. sativa (Spring vetch)*
    sativa ssp. nigra (Narrow-leaved vetch)*
    villosa ssp. varia (Smooth winter vetch)*
    villosa ssp. villosa (Hairy winter vetch)*
Viguiera
    laciniata, see Bahiopsis laciniata
    parishii, see Bahiopsis parishii
Vinca major (Periwinkle)*
Viola
    adunca ssp. adunca (Western dog violet)
    douglasii (Douglas's violet)
    lobata ssp. lobata (Yellow violet)
    macloskeyi (Macloskie's violet)
    pedunculata (Johnny jump up)
    pinetorum ssp. grisea (Gray-leaved violet)
    pinetorum ssp. pinetorum (Pine violet)
    purpurea ssp. mohavensis (Mojave goosefoot violet)
    purpurea ssp. purpurea (Goosefoot violet)
    purpurea ssp. quercetorum (Oak violet)
    sheltonii (Shelton's violet)
Vitis girdiana (Wild grape)
Vulpia
    microstachys, see Festuca microstachys
    myuros var. hirsuta, see Festuca myuros
    octoflora var. hirtella, see Festuca octoflora
    octoflora var. octoflora, see Festuca octoflora
Washingtonia filifera (California fan palm)
Woodsia oregana (Oregon cliff fern)
Woodwardia fimbriata (Giant chain fern)
Wyethia ovata (Mule's ears)
Xanthisma gracile (Slender goldenweed)
Xanthium
    spinosum (Spiny cocklebur)
    strumarium (Cocklebur)
Xylococcus bicolor (Mission manzanita)
Xylorhiza
    cognata (Mecca-aster)
    orcuttii (Orcutt's woody-aster)
    tortifolia var. tortifolia (Mojave-aster)
Yabea microcarpa (California hedge-parsley)
Yucca
    baccata var. baccata (Banana yucca)
    brevifolia (Joshua tree)
    schidigera (Mojave yucca)
    whipplei, see Hesperoyucca whipplei
Zeltnera venustum (Canchalagua)
Zigadenus
    brevibracteatus, see Toxicoscordion brevibracteatum
    fremontii, see Toxicoscordion fremontii
    venenosus var. venenosus, see Toxicoscordion venenosum var. venenosum
Ziziphus parryi var. parryi (Lotebush)