Abert's sanvitalia (Sanvitalia abertii)
Abrams' alumroot (Heuchera abramsii)
Abronia, Coville's dwarf (Abronia nana ssp. covillei)
Acacia,
    Catclaw (Acacia greggii)
    Plume (Albizia lophantha)*
    Sweet (Acacia farnesiana var. farnesiana)*
Acton encelia (Encelia actoni)
Adams' manzanita (Arctostaphylos glandulosa ssp. adamsii)
Adder's-tongue, California (Ophioglossum californicum)
Adobe popcorn flower (Plagiobothrys acanthocarpus)
Adolphia, California (Adolphia californica)
African asparagus fern (Asparagus asparagoides)*
African daisy (Osteospermum ecklonis)*
African mustard (Malcolmia africana)*
Agave,
    Desert (Agave deserti)
    Shaw's (Agave shawii)
    Utah (Agave utahensis)
Alaska rein orchid (Piperia unalascensis)
Alder, White (Alnus rhombifolia)
Aleppo pine (Pinus halepensis)*
Alfalfa (Medicago sativa)*
Algodones Dunes sunflower (Helianthus niveus ssp. tephrodes)
Alkali draba (Cusickiella douglasii)
Alkali goldenbush
    (Isocoma acradenia var. acradenia)
    (Isocoma acradenia var. eremophila)
Alkali heath (Frankenia salina)
Alkali mallow (Malvella leprosa)
Alkali mariposa lily (Calochortus striatus)
Alkali sacaton (Sporobolus airoides)
Alkali weed (Cressa truxillensis)
Allseed, Four-leaf (Polycarpon tetraphyllum)*
Almond, Desert (Prunus fasciculata var. fasciculata)
Alpine aster (Aster alpigenus var. andersonii)
Alpine gold hulsea (Hulsea algida)
Alpine gooseberry (Ribes lasianthum)
Alpine pearlwort (Sagina saginoides)
Alpine shooting star (Dodecatheon alpinum)
Alpine sulpher-flowered buckwheat (Eriogonum umbellatum var. minus)
Alumroot,
    Abrams' (Heuchera abramsii)
    Island (Heuchera maxima)
    Mount Laguna (Heuchera brevistaminea)
    Pink (Heuchera rubescens var. alpicola)
    San Bernardino Mountains (Heuchera parishii)
    Shaggy-haired (Heuchera hirsutissima)
    Urn-flowered (Heuchera elegans)
Alverson's spinystar (Escobaria vivipara alversonii)
Alyssum,
    Desert (Lepidium fremontii var. fremontii)
    Sweet (Lobularia maritima)*
Amaranth,
    California (Amaranthus californicus)
    Fringed (Amaranthus fimbriatus)
    Pigweed (Amaranthus albus)*
    Prostrate (Amaranthus blitoides)
    Torrey's (Amaranthus torreyi)
Ambrosia, San Diego (Ambrosia pumila)
American dogwood (Cornus sericea ssp. sericea)
American speedwell (Veronica americana)
American vetch (Vicia americana var. americana)
American wild carrot (Daucus pusillus)
Ammannia, Red (Ammannia coccinea)
Amsonia, Woolly (Amsonia tomentosa)
Anderson thornbush (Lycium andersonii)
Anderson's lupine (Lupinus andersonii)
Angelica, Woolly (Angelica tomentosa)
Angel's gilia, see Chaparral gilia
Angel's trumpet (Brugmansia sp.)**
Angled-stem buckwheat (Eriogonum angulosum)
Annual bedstraw (Galium aparine)*
Annual bur-sage (Ambrosia acanthicarpa)
Annual malacothrix (Malacothrix clevelandii)
Annual moonwort (Lunaria annua)*
Antelope bush (Purshia tridentata var. glandulosa)
Apache plume (Fallugia paradoxa)
Apricot, Desert (Prunus fremontii)
Apricot mallow (Sphaeralcea ambigua var. ambigua)
Aralia, California (Aralia californica)
Argus gilia (Gilia brecciarum ssp. neglecta)
Arizona chalk dudleya (Dudleya arizonica)
Arizona hymenoxys (Hymenoxys acaulis var. arizonica)
Arizona lupine (Lupinus arizonicus)
Arizona popcorn flower (Plagiobothrys arizonicus)
Arizona springparsley (Cymopterus multinervatus)
Arizona spurge (Chamaesyce arizonica)
Arrowleaf (Pleurocoronis pluriseta)
Arrowleaf butterweed (Senecio triangularis)
Arrowleaf saltbush (Atriplex triangularis)
Arrowscale (Atriplex phyllostegia)
Arrowweed (Pluchea sericea)
Arroyo lupine (Lupinus succulentus)
Arroyo willow (Salix lasiolepis)
Ash,
    California (Fraxinus dipetala)
    Velvet (Fraxinus velutina)
Ashy silktassel (Garrya flavescens)
Ashy spike-moss (Selaginella cinerascens)
Ashy-gray paintbrush (Castilleja cinerea)
Ashyleaf buckwheat (Eriogonum cinereum)
Asian mustard (Brassica tournefortii)*
Aster,
    Alpine (Aster alpigenus var. andersonii)
    California (Lessingia filaginifolia var. filaginifolia)
    Chile (Aster chilensis)
    Desert hoary (Machaeranthera canescens var. leucanthemifolia)
    Greata's (Aster greatae)
    Hoary (Machaeranthera canescens var. canescens)
    Long-leaved (Aster ascendens)
    Mexican (Cosmos bipinnatus)*
    Mojave- (Xylorhiza tortifolia var. tortifolia)
    San Bernardino (Aster bernardinus)
    Short-leaved cliff (Malacothrix saxatilis var. tenuifolia)
    Slim (Aster subulatus var. ligulatus)
    Spiny (Chloracantha spinosa var. spinosa)
    Western lanceleaf (Aster lanceolatus ssp. hesperius)
    Western mountain (Aster occidentalis var. occidentalis)
    Ziegler's (Machaeranthera canescens var. ziegleri)
Asthmaweed (Conyza floribunda)*
Athel (Tamarix aphylla)*
Athysanus, Dwarf (Athysanus pusillus)
Austin's beardtongue (Penstemon floridus var. austinii)
Australian brass-buttons (Cotula australis)*
Australian saltbush (Atriplex semibaccata)*
Autumn dwarf gentian (Gentianella amarella ssp. acuta)
Aven Nelson's phacelia (Phacelia anelsonii)
Avens, Large-leaved (Geum macrophyllum)
Ayenia (Ayenia compacta)
Azalea
    [Common] (Rhododendron sp.)**
    Western (Rhododendron occidentale)
Baby blue eyes,
    (Nemophila menziesii var. integrifolia)
    (Nemophila menziesii var. menziesii)
Baby sun rose (Aptenia cordifolia)*
Baccharis,
    Broom (Baccharis sarothroides)
    Desert (Baccharis sergiloides)
    Emory (Baccharis emoryi)
    Encinitas (Baccharis vanessae)
    Malibu (Baccharis malibuensis)
    Plummer's (Baccharis plummerae ssp. plummerae)
    Salt marsh (Baccharis douglasii)
Bahia,
    Many-flowered (Schkuhria multiflora var. multiflora)
    Ragged-leaf (Bahia dissecta)
Baja birdbush (Ornithostaphylos oppositifolia)
Baja fairy duster (Calliandra californica)**
Bajada lupine (Lupinus concinnus)
Baldwin Lake linanthus (Linanthus killipii)
Balloon clover (Trifolium depauperatum var. truncatum)
Balsamroot, Deltoid (Balsamorhiza deltoidea)
Banana yucca (Yucca baccata)
Barberry,
    California (Berberis pinnata ssp. pinnata)
    Fremont's (Berberis fremontii)
    Nevin's (Berberis nevinii)
Barbwire Russian thistle (Salsola paulsenii)*
Barley,
    Bobtail (Hordeum intercedens)
    Foxtail (Hordeum murinum ssp. glaucum)*
    Hare (Hordeum murinum ssp. leporinum)*
    Meadow (Hordeum brachyantherum ssp. californicum)
Barrel cactus,
    California (Ferocactus cylindraceus var. cylindraceus)
    Coast (Ferocactus viridescens)
    LeConte's (Ferocactus cylindraceus var. lecontei)
Basin butterweed (Senecio multilobatus)
Basin sagebrush (Artemisia tridentata ssp. tridentata)
Basket rush (Juncus textilis)
Bassia, Five-hook (Bassia hyssopifolia)
Bay, California (Umbellularia californica)
Beach primrose,
    Channel Islands (Camissonia cheiranthifolia ssp. cheiranthifolia)
    [Common] (Camissonia cheiranthifolia ssp. suffruticosa)
Beach morning glory (Calystegia soldanella)
Beach saltbush (Atriplex leucophylla)
Beaked penstemon (Penstemon rostriflorus)
Bear Valley milkvetch (Astragalus lentiginosus var. sierrae)
Bear Valley pyrrocoma (Pyrrocoma uniflora var. gossypina)
Bear Valley sandwort (Arenaria ursina)
Bear Valley woollypod (Astragalus leucolobus)
Beard grass, Ditch (Polypogon interruptus)*
Bearded clover (Trifolium barbigerum)
Bearded cryptantha (Cryptantha barbigera)
Beardtongue,
    Austin's (Penstemon floridus var. austinii)
    Cleveland's (Penstemon clevelandii var. clevelandii)
    Desert (Penstemon fruticiformis var. fruticiformis)
    Limestone (Penstemon calcareus)
    San Bernardino (Penstemon caesius)
    San Gabriel (Penstemon labrosus)
    San Gabriel (yellow variant) (Penstemon labrosus)
    San Jacinto (Penstemon clevelandii var. connatus)
    Stephens' (Penstemon stephensii)
Beargrass,
    Chaparral (Nolina cismontana)
    [Common] (Nolina bigelovii)
Beautiful hulsea (Hulsea vestita ssp. callicarpha)
Beautiful rock-cress (Arabis pulchra var. pulchra)
Beavertail cactus,
    [Common] (Opuntia basilaris var. basilaris)
    Short-joint (Opuntia basilaris var. brachyclada)
Bedstraw,
    Annual (Galium aparine)*
    Boxwood-leaved (Galium buxifolium)
    Catalina Island (Galium catalinense)
    Climbing (Galium nuttallii ssp. nuttallii)
    Leafy (Galium angustifolium ssp. foliosum)
    Narrow-leaved (Galium angustifolium ssp. angustifolium)
    Nodding (Galium hallii)
    Nuttall's island (Galium nuttallii ssp. insulare)
    Parish's (Galium parishii)
    Phlox-leaved (Galium andrewsii ssp. andrewsii)
    Phlox-leaved (Galium andrewsii ssp. intermedium)
    San Antonio Canyon (Galium angustifolium ssp. gabrielense)
    San Jacinto Mountains (Galium angustifolium ssp. jacinticum)
    San Miguel Island (Galium californicum ssp. miguelense)
    Slender (Galium angustifolium ssp. gracillimum)
    Small (Galium trifidum var. pusillum)
    Star-flowered (Galium stellatum var. eremicum)
    Tiny (Galium murale)*
    Wall (Galium parisiense)*
Bee balm (Monarda pectinata)
Bee blossom, Wavyleaf (Gaura sinuata)*
Beet, Common (Beta vulgaris)*
Beetle spurge (Euphorbia eriantha)
Beggar-ticks,
    Common (Bidens pilosa var. pilosa)
    Smooth (Bidens laevis)
Bell gilia (Gilia campanulata)
Bengal dayflower (Commelina benghalensis)**
Bentgrass,
    Green (Agrostis viridis)*
    Idaho (Agrostis idahoensis)
    Seashore (Agrostis pallens)
Bentham lupine (Lupinus benthamii)
Bergamot mint (Mentha Xpiperita var. citrata)*
Bermuda buttercup (Oxalis pes-caprae)*
Bermuda grass (Cynodon dactylon)*
Bernardia (Bernardia myricifolia)
Big Bear checkerbloom (Sidalcea pedata)
Big Bear Valley phlox (Phlox dolichantha)
Big galleta grass (Pleuraphis rigida)
Big leaf maple (Acer macrophyllum)
Big leaf mistletoe (Phoradendron macrophyllum)
Bigberry manzanita (Arctostaphylos glauca)
Bigbract verbena (Verbena bracteata)
Bigcone spruce (Pseudotsuga macrocarpa)
Bigelow's coreopsis (Coreopsis bigelovii)
Bigelow's desert four o'clock (Mirabilis bigelovii var. bigelovii)
Bigelow's monkeyflower (Mimulus bigelovii var. bigelovii)
Bigelow's monkeyflower (Mimulus bigelovii var. cuspidatus)
Bigelow's sneezeweed (Helenium bigelovii)
Bigelow's spike-moss (Selaginella bigelovii)
Bigpod ceanothus (Ceanothus megacarpus var. megacarpus)
Bindweed
    Coast range (Calystegia collina ssp. venusta)
    [Common] (Convolvulus arvensis)*
Birch-leaf mountain mahogany (Cercocarpus betuloides var. betuloides)
Bird-of-paradise (Strelitzia reginae)**
Birdnest buckwheat (Eriogonum nidularium)
Bird's beak,
    Bristly (Cordylanthus rigidus ssp. setigerus)
    Nevin's (Cordylanthus nevinii)
    Orcutt's (Cordylanthus orcuttianus)
    Purple (Cordylanthus parviflorus)
    Salt marsh (Cordylanthus maritimus ssp. maritimus)
Birdseye gilia (Gilia tricolor)
Bird's-foot fern (Pellaea mucronata var. mucronata)
Bird's-foot trefoil,
    Canyon (Lotus argyraeus var. argyraeus)
    [Common] (Lotus corniculatus)*
    San Clemente Island (Lotus argophyllus var. adsurgens)
    Santa Cruz Island (Lotus argophyllus var. niveus)
Bishop pine (Pinus muricata)
Bistort, Western (Polygonum bistortoides)
Bitter cherry (Prunus emarginata)
Bitter cress (Cardamine oligosperma)
Bitter gooseberry (Ribes amarum)
Bitterroot (Lewisia rediviva)
Black cottonwood (Populus balsamifera ssp. trichocarpa)
Black grama (Bouteloua eriopoda)
Black hair nettle (Hesperocnide tenella)
Black locust (Robinia pseudoacacia)*
Black medick (Medicago lupulina)*
Black mustard (Brassica nigra)*
Black oak, California (Quercus kelloggii)
Black sage (Salvia mellifera)
Black sagebrush (Artemisia nova)
Black walnut,
    California (female flowers) (Juglans californica var. californica)
    California (fruit) (Juglans californica var. californica)
    California (male flowers) (Juglans californica var. californica)
Black willow, Goodding's (Salix gooddingii)
Black-banded rabbitbrush (Chrysothamnus paniculatus)
Blackberry,
    California (Rubus ursinus)
    California, fruit (Rubus ursinus)
Blackbrush (Coleogyne ramosissima)
Bladder senna (Colutea arborescens)*
Bladderpod,
    [Common] (Isomeris arborea)
    King's (Lesquerella kingii ssp. kingii)
    San Bernardino Mountains (Lesquerella kingii ssp. bernardina)
Blazing star,
    Bushy (Mentzelia dispersa)
    Giant (Mentzelia laevicaulis)
    Inyo (Mentzelia oreophila)
    Lindley's (Mentzelia lindleyi)
    Mountain (Mentzelia montana)
    Pacific (Mentzelia obscura)
    Polished (Mentzelia polita)
    Reflexed (Mentzelia reflexa)
    Sand (Mentzelia involucrata)
    Veatch's (Mentzelia veatchiana)
    Whitestem (Mentzelia albicaulis)
Bleeding hearts (Dicentra ochroleuca)
Blessed thistle (Cnicus benedictus)*
Blow wives (Achyrachaena mollis)
Blue dicks (Dichelostemma capitatum ssp. capitatum)
Blue flag, Western (Iris missouriensis)
Blue flax, Western (Linum lewisii var. lewisii)
Blue grama (Bouteloua gracilis)
Blue gum (Eucalyptus globulus)*
Blue larkspur (Delphinium parryi ssp. parryi)
Blue oak (Quercus douglasii)
Blue sage (Salvia dorrii var. dorrii)
Blue sage (Salvia dorrii var. pilosa)
Blue toadflax (Linaria canadensis)
Blue violet (Viola adunca)
Blue wildrye (Elymus glaucus ssp. glaucus)
Bluebells, Desert (Phacelia campanularia)
Bluecup,
    San Gabriel (Githopsis diffusa ssp. diffusa)
    White-flowered (Githopsis diffusa ssp. candida)
Bluecurls,
    Parish's (Trichostema parishii)
    Smallflower (Trichostema micranthum)
    Southern (Trichostema austromontanum ssp. austromontanum)
    Woolly (Trichostema lanatum)
Blue-eyed grass,
    [Common] (Sisyrinchium bellum)
    Idaho (Sisyrinchium idahoense var. occidentale)
Bluegrass,
    Bulbous (Poa bulbosa)*
    Fendler's (Poa fendleriana ssp. longiligula)
    One-sided (Poa secunda ssp. secunda)
    Rush (Poa secunda ssp. juncifolia)
    San Bernardino (Poa atropurpurea)
    Sand-dune (Poa douglasii)
Bluish spike-moss (Selaginella asprella)
Blue-witch nightshade (Solanum umbelliferum)
Bobtail barley (Hordeum intercedens)
Boccone's sand spurrey (Spergularia bocconei)*
Boerhavia,
    Fivewing (Boerhavia intermedia)
    Red (Boerhavia coccinea)
    Slender (Boerhavia triquetra)
    Wright's (Boerhavia wrightii)
Bog orchid,
    Sparse-flowered (Platanthera sparsiflora)
    White-flowered (Platanthera leucostachys)
Bog wintergreen (Pyrola asarifolia ssp. asarifolia)
Bog yellow-cress, Western (Rorippa palustris var. occidentalis)
Boisduvalia, Smooth (Epilobium pygmaeum)
Bolander's monkeyflower (Mimulus bolanderi)
Boojum tree (Idria columnaris)
Booth's intermediate sun cup (Camissonia boothii ssp. intermedia)
Booth's shredding sun cup (Camissonia boothii ssp. condensata)
Bottlebrush (Callistemon sp.)**
Borrego milkvetch (Astragalus lentiginosus var. borreganus)
Bougainvillea (Bougainvillea sp.)**
Boundary goldenbush (Ericameria brachylepis)
Bowlesia (Bowlesia incana)
Bownut cryptantha (Cryptantha cinerea var. abortiva)
Box elder (Acer negundo var. californicum)
Boxthorn,
    California (Lycium californicum)
    Cooper's (Lycium cooperi)
Boxwood-leaved bedstraw (Galium buxifolium)
Boykinia,
    Coast (Boykinia occidentalis)
    Round-leaved (Boykinia rotundifolia)
Bracken fern (Pteridium aquilinum var. pubescens)
Bracted gumplant (Grindelia camporum var. bracteosum)
Brake, Cliff (Pellaea truncata)
Branched hareleaf (Lagophylla ramosissima ssp. ramosissima)
Branching phacelia,
    (Phacelia ramosissima var. latifolia)
    (Phacelia ramossisima var. ramossisima)
Brandegea (Brandegea bigelovii)
Brandegee's sage (Salvia brandegeei)
Brass-buttons,
    Australian (Cotula australis)*
    [Common] (Cotula coronopifolia)*
Braunton's rattleweed (Astragalus brauntonii)
Brazilian pepper (Schinus terebinthifolius)*
Brazilian plume (Justicia aurea)**
Brewer's fleabane (Erigeron breweri var. breweri)
Brewer's lupine (Lupinus breweri var. breweri)
Brewer's monkeyflower (Mimulus breweri)
Brewer's navarretia (Navarretia breweri)
Brewer's oak (Quercus garryana var. breweri)
Brewer's red maids (Calandrinia breweri)
Brickellbush,
    California (Brickellia californica)
    Desert (Brickellia desertorum)
    Gum-leaved (Brickellia multiflora)
    Little-leaved (Brickellia microphylla)
    Narrow-leaved (Brickellia oblongifolia var. linifolia)
    Nevin's (Brickellia nevinii)
    Shrubby (Brickellia frutescens)
    Spearleaf (Brickellia arguta)
    Woolly (Brickellia incana)
Bright white (Prenanthella exigua)
Bristlecone pine (Pinus longaeva)
Bristly bird's beak (Cordylanthus rigidus ssp. setigerus)
Bristly golden-aster (Heterotheca sessiliflora ssp. echioides)
Bristly langloisia (Langloisia setosissima ssp. setosissima)
Bristly matilija poppy (Romneya trichocalyx)
Bristly ox-tongue (Picris echioides)*
Bristly pectocarya (Pectocarya setosa)
Bristly-leaved rock-cress (Arabis rectissima var. rectissima)
Brittle fern (Cystopteris fragilis)
Brittle spineflower (Chorizanthe brevicornu var. brevicornu)
Brittlebush (Encelia farinosa)
Broad-flowered gilia (Gilia latiflora ssp. latiflora)
Broad-fruited pectocarya (Pectocarya platycarpa)
Broadleaf gilia (Gilia latifolia)
Broadleaf plantain (Plantago major)*
Broadleaf stonecrop (Sedum spathulifolium)
Broad-leaved cattail (Typha latifolia)
Broad-leaved lotus (Lotus crassifolius var. crassifolius)
Broad-leaved lupine (Lupinus latifolius var. latifolius)
Broad-leaved stillingia (Stillingia spinulosa)
Broad-seeded rock-cress (Arabis platysperma var. platysperma)
Brodiaea,
    Earth (Brodiaea terrestris ssp. kernensis)
    Harvest (Brodiaea elegans)
    Orcutt's (Brodiaea orcuttii)
    Santa Rosa basalt (Brodiaea santarosae)
    Thread-leaved (Brodiaea filifolia)
Brome,
    California (Bromus carinatus var. carinatus)
    Red (Bromus madritensis ssp. rubens)*
    Ripgut (Bromus diandrus)*
    Seaside (Bromus carinatus var. maritimus)
Broom,
    Dune (Chaetadelpha wheeleri)
    French (Genista monspessulana)*
    Mediterranean (Genista linifolia)*
    Portuguese (Cytisus striatus)*
    Spanish (Spartium junceum)*
    Turpentine- (Thamnosma montana)
Broom baccharis (Baccharis sarothroides)
Broom groundsel (Senecio spartioides)
Broom snakeweed (Gutierrezia sarothrae)
Broom-rape,
    California (Orobanche californica ssp. feudgei)
    Chaparral (Orobanche bulbosa)
    Clustered (Orobanche fasciculata)
    Cooper's (Orobanche cooperi)
    Naked (Orobanche uniflora)
    Parish's (Orobanche parishii ssp. parishii)
    Rock Creek (Orobanche valida ssp. valida)
    Short-lobed (Orobanche parishii ssp. brachyloba)
Brown microseris (Stebbinsoseris heterocarpa)
Brown-eyed primrose,
    Death Valley (Camissonia claviformis ssp. funerea)
    Mojave (Camissonia claviformis ssp. claviformis)
    Peirson's (Camissonia claviformis ssp. peirsonii)
Brown-headed rush (Juncus phaeocephalus var. paniculatus)
Buckbrush (Ceanothus cuneatus var. cuneatus)
Buckeye,
    California (Aesculus californica)
    California, seed (Aesculus californica)
Buckhorn cholla (Opuntia acanthocarpa var. coloradensis)
Buckwheat,
    Angled-stem (Eriogonum angulosum)
    Ashyleaf (Eriogonum cinereum)
    Birdnest (Eriogonum nidularium)
    California (Eriogonum fasciculatum var. fasciculatum)
    Conejo (Eriogonum crocatum)
    Cushenbury (Eriogonum ovalifolium var. vineum)
    Davidson's (Eriogonum davidsonii)
    Desert wild (Eriogonum fasciculatum var. polifolium)
    Dune (Eriogonum deserticola)
    East Mojave (Eriogonum fasciculatum var. flavoviride)
    Few-flowered naked (Eriogonum nudum var. pauciflorum)
    Flatcrown (Eriogonum deflexum)
    Flat-topped (Eriogonum plumatella)
    Gilman's (Eriogonum gilmanii)
    Heermann's (Eriogonum heermannii var. argense)
    Heermann's (Eriogonum heermannii var. floccosum)
    Island (Eriogonum grande var. grande)
    Johnston's (Eriogonum microthecum var. johnstonii)
    Kennedy's (Eriogonum kennedyi var. kennedyi)
    Kidney-leaved (Eriogonum reniforme)
    Knotty (Eriogonum wrightii var. nodosum)
    Leafy (Eriogonum fasciculatum var. foliolosum)
    Longstem (Eriogonum elongatum var. elongatum)
    Munz's (Eriogonum umbellatum var. munzii)
    Nevada (Eriogonum umbellatum var. nevadense)
    Oval-leaved (Eriogonum ovalifolium var. ovalifolium)
    Palmer's (Eriogonum palmerianum)
    Panamint (Eriogonum panamintense)
    Parish's (Eriogonum parishii)
    Pineland (Eriogonum molestum)
    Red-flowered (Eriogonum grande var. rubescens)
    Reveal's (Eriogonum contiguum)
    Rixford's (Eriogonum rixfordii)
    Rock (Eriogonum saxatile)
    San Jacinto (Eriogonum apiculatum)
    Santa Cruz Island (Eriogonum arborescens)
    Seacliff (Eriogonum parvifolium)
    Slender (Eriogonum gracile var. gracile)
    Southern alpine (Eriogonum kennedyi var. alpigenum)
    Southern mountain (Eriogonum kennedyi var. austromontanum)
    Spotted (Eriogonum maculatum)
    Sulpher-flowered (Eriogonum umbellatum var. subaridum)
    Thomas' (Eriogonum thomasii)
    Thorne's (Eriogonum thornei)
    Varicolored (Eriogonum umbellatum var. versicolor)
    Weston's (Eriogonum nudum var. westonii)
    Wildrose Canyon (Eriogonum eremicola)
    Wright's (Eriogonum wrightii var. membranaceum)
    Wright's (Eriogonum wrightii var. subscaposum)
    Wright's (Eriogonum wrightii var. wrightii)
Buffalo-berry (Shepherdia argentea)
Bulbous bluegrass (Poa bulbosa)*
Bull mallow (Malva nicaeensis)*
Bull thistle (Cirsium vulgare)*
Bulrush,
    California (Scirpus californicus)
    Marsh (Scirpus maritimus)
Bur-chervil (Anthriscus caucalis)*
Burhead (Echinodorus berteroi)
Burlew's onion (Allium burlewii)
Burning bush (Euonymus occidentalis var. parishii)
Burrobush (Ambrosia dumosa)
Bur-sage,
    Annual (Ambrosia acanthicarpa)
    Goosefoot (Ambrosia chenopodiifolia)
    Woolly (Ambrosia eriocentra)
Bush anenome (Carpenteria californica)**
Bush chinquapin (Chrysolepis sempervirens)
Bush chinquapin seed pod (Chrysolepis sempervirens)
Bush lupine,
    Coast (Lupinus arboreus)
    [Common] (Lupinus longifolius)
    Douglas's Silver (Lupinus albifrons var. douglasii)
    Hall's (Lupinus excubitus var. hallii)
    Johnston's (Lupinus excubitus var. johnstonii)
    Silver (Lupinus albifrons var. albifrons)
Bush mallow,
    [Common] (Malacothamnus fasciculatus)
    Fremont's (Malacothamnus fremontii)
    Indian Valley (Malacothamnus aboriginum)
    Pink-flowered (Malacothamnus marrubioides)
    San Clemente Island (Malacothamnus clementinus)
    Yellow-stemmed (Malacothamnus densiflorus)
Bush monkeyflower
    [Common] (Mimulus aurantiacus)}
    Island (Mimulus flemingii)
Bush muhly (Muhlenbergia porteri)
Bush poppy (Dendromecon rigida)
Bush sage,
    [Common] Mexican (Salvia leucantha)
    Purple Mexican (Salvia leucantha cv. "Midnight")
Bush senecio (Senecio flaccidus var. douglasii)
Bush spurge (Euphorbia characias)*
Bush sunflower (Encelia californica)
Bushloving cryptantha (Cryptantha dumetorum)
Bushrue (Cneoridium dumosum)
Bushy blazing star (Mentzelia dispersa)
Bushy cryptantha (Cryptantha racemosa)
Buttercup,
    Bermuda (Oxalis pes-caprae)*
    California (Ranunculus californicus)
    Rocky Mountain (Ranunculus cymbalaria var. saximontanus)
    Small water-plantain (Ranunculus alismifolius)
    Water (Ranunculus aquatilis var. capillaceus)
    Western (Ranunculus occidentalis)
Butterfly bush, Panamint (Buddleja utahensis)
Butterfly mariposa lily (Calochortus venustus)
Butterweed,
    Arrowleaf (Senecio triangularis)
    Basin (Senecio multilobatus)
Button-celery, San Diego (Eryngium aristulatum var. parishii)