T

                   In the following names, the stressed vowel is the one preceding the stress mark. It is not always
                  easy to ascertain where such stress should be placed, especially in the case of epithets derived
                  from personal names. I have tried to follow the principle of maintaining the stress of the original
                  name as outlined in the Jepson Manual, and have abandoned it only when it was just too awkward.
                  In the case of some names, I have listed them twice, reflecting either some disagreement or conflict
                  in the rules of pronunciation, some uncertainty on my part as to the correct pronunciation, or simply
                  that sometimes there is no single correct pronunciation. In other instances, the way I record it is just
                  that which sounds right to my ear.

• tabernaemonta'ni: after Jacob Theodor von Bergzabern (1520-1590). The following is from Stearn's Dictionary of Plant Names: "...personal physician to the Count of the Palatine at Heidelberg, West Germany. He Latinized is name as Tabernamontanus [which means Tavern in the mountains] and is also commemorated by species named for him in Amsonia, Potentilla and Scirpus. He was the author of a celebrated herbal Neuw Kreuterbuch (1588-1591), of which the illustrations were issued separately at Frankfurt-am-Main in 1590 under the title Eicones Plantarum. The woodcuts were mostly copied from those in other herbals but make an attractive book. The London printer, John Norton, acquired them from the Frankfurt printer Nicholaus Bassaeus and used them in 1597 to illustrate Garard's Herball." Many of the websites that mention von Bergzabern have to do with beer and brewing, a subject he was apparently very interested in (ref. Scirpus tabernaemontani)
• Taenia'therum: from the Greek tainia, "a band or ribbon," and ather, "an awn," referring to the flat or ribboned awn of the lemma (ref. genus Taeniatherum)
• Tage'tes: named after the Etruscan god Tages who supposedly emerged from the earth as it was being ploughed and was imbued with the power of divination (ref. genus Tagetes)
• tageti'na: possibly from genus Tagetes (ref. Navarretia tagetina)
• tahoen'sis: of or from the area of Lake Tahoe (ref. Carex tahoensis)
• Tam'arix: the Latin name for this plant derived from the Tamaris River in Spain (ref. genus Tamarix)
• tanacetifo'lia: tansy-leaved, with leaves like Tanacetum (ref. Machaeranthera tanacetifolia, Phacelia tanacetifolia)
• Tanace'tum: from the medieval Latin name tanazita, in turn derived from Greek athanasia, "immortality," of uncertain application to this taxa (ref. genus Tanacetum)
• tandilen'sis: named for the Sierra de Tandil, near the center of Buenos Aires Province, Argentina, where this taxon is native (ref. Agrostis tandilensis)
• taraxaco'ides: having a resemblance to Taraxacum (ref. Leontodon taraxacoides)
• Tarax'acum: medieval name traceable through Arabic to the Persian talkh chakok, meaning "bitter herb (ref. genus Taraxacum)
• taraxacifo'lia: with leaves like genus Taraxacum
• tardiflor'a: late-flowering or developing
• tarminia'na: apparently named after a Columbian agrnomist and professor named Tarmín de Jesus Campos Espinosa (1947- ) who was working with fruit researchers in Columbia and introduced them to the study of passionfruits (ref. Passiflora tarminiana)
• tatar'ica: from the common name of this species, Russian blue lettuce, I infer that that the name tatarica refers to the Tatars, a primarily Turkic peoples found in areas of the former U.S.S.R. Lonicera tatarica is native to Siberia and the assignment of the name of the native Lactuca tatarica was based on a plant from Siberia described by J. G. Gmelin as 'Sonchus foliis lanceolatis sessilibus dentatis, floribus corymbosis, caulibus glabris'. Linnaeus renamed it Sonchus tataricus and C.A. Meyer transfered it to Lactuca in 1831 (ref. Lactuca tatarica, Lonicera tatarica)
• taur'icum: of or from the Crimean region of the Mediterranean, which in ancient times was referred to as Taurica Chersonesus (ref. Onopordum tauricum)
• Tau'schia: named after Ignaz Friedrich Tausch (1793-1848), a Czech professor of botany, director of the garden of the Duke of Canal de Malabaillas in Prague, and author of a flora of Bohemia in 1831 (ref. genus Tauschia)
• taxifo'lia: with leaves like those of the genus Taxus or yew (ref. Suaeda taxifolia)
• Ta'xus: the Latin name for the yew tree (ref. genus Taxus)
• tay'lorii: after Dean William Taylor (1948- ), a California botanist who is particularly interested in mountain regions like the Sierras and the White Mountains. He studied with G. Ledyard Stebbins and received his doctoral degree from UC Davis. He has been a lecturer at San Francisco State University, University of Colorado at Boulder, University of California at Santa Cruz, and a research botanist at Oregon State University. He was the first Vice-President of the California Botanical Society and is currently on the Rare Plant Scientific Advisory Committee of the California Native Plant Society. He has been deeply involved in the conservation of endangered plants (ref. Erythronium taylorii)
• tazet'ta: apparently an Italian vernacular name from tazza, "a small cup," referring to the form of the corona, which is a petal-like or crown-like structure between the petals and stamens in some flowers (ref. Narcissus tazetta)
• Teco'ma: abbreviated from the Mexican name tecomaxochitl (ref. genus Tecoma)
• Tecomar'ia: takes its name from Tecoma, a species which it closely resembles (ref. genus Tecomaria)
• tecopen'sis: named after Tecopa, a hot springs community southeast of Death Valley National Park (ref. Cordylanthus tecopensis)
• tector'um: relating to the roofs of houses, this was a name used by Linnaeus for various Swedish plants that grew on thatched roofs (ref. Bromus tectorum, Crepis tectorum)
• Teesdal'ia: after Robert Teesdale (1740-1804), an English botanist and horticulturist from Yorkshire (ref. genus Teesdalia)
• tegetario'ides: like tegetarius. This taxon is similar to Astragalus kentrophyta var. tegetarius (ref. Astragalus tegetarioides)
• tegetar'ius: from the Latin tegetarius, "a mat maker," from teges or tegetis, "a covering, mat" (ref. Astragalus kentrophyta var. tegetarius)
• tehamen'se: of or from Tehama County in northern California north of Sacramento (ref. Hesperolinon tehamense)
• telmatei'a: of or referring to wet meadows or pools (ref. Equisetum telmateia ssp. braunii)
• tembloren'se: same as next entry (ref. Eriogonum temblorense)
• temblorien'sis: named for the Temblor Range in south-central California bordering on the San Joaquin Valley and the Carrizo Plain (ref. Clarkia tembloriensis)
• temulen'tum: from the Latin temulus for "drunken, nodding, top-heavy" (ref. Lolium temulentum)
• ten'ax: gripping, tenacious or sticky in one sense, and firm, persistant or stubborn in another, from teneo or tenere, "to hold" (ref. Iris tenax, Xerophyllum tenax)
• tenebro'sa: growing in shady places
• tenel'la/tenel'lum/tenel'lus: from the Latin meaning "quite delicate, dainty" (ref. Gentianella tenella, Hesperocnide tenella,Osmadenia tenella, Physaria tenella, Lithophragma tenellum, Plagiobothrys tenellus, Psilocarphus tenellus)
• te'ner: slender, tender, soft (ref. Erigeron tener, Astragalus tener)
• tene'rrima/tener'rimus: very slender (ref. Gilia tenerrima, Poa tenerrima, Rorippa tenerimma, Sonchus tenerrimus)
• ten'ue: see tenuis (ref. Galium porrigens var. tenue)
• tenui-: prefix indicating the characteristic of being slender
• tenuicau'lis: with fine stems
• tenuiflor'a/tenuiflor'us: with fine or delicate flowers (ref. Gilia tenuiflora, Carduus tenuiflorus)
• tenuifo'lia/tenuifo'lius: with finely-divided, slender leaves (ref. Calystegia macrostegia ssp. tenuifolia, Diplotaxis tenuifolia, Ipomopsis tenuifolia, Malacothrix saxatilis var. tenuifolia, Potamogeton alpinus ssp. tenuifolius)
• tenuilo'ba: with finely-divided or slender lobes (ref. Mirabilis tenuiloba)
• tenuiloba'tum: see tenuiloba above (ref. Solanum tenuilobatum)
• tenu'ipes: with a slender stalk (ref. Hydrophyllum tenuipes)
• tenu'is: slender (ref. Castilleja tenuis, Lessingia tenuis, Nemacladus tenuis, Malperia tenuis, Orcuttia tenuis)
• tenuisec'ta/tenuisec'tum: thinly or narrowly cut (ref. Verbena tenuisecta, Cirsium arizonicum var. tenuisectum)
• tenuis'sima/tenuis'simus: very slender (ref. Iris tenuissima, Potamogeton pusillus var. tenuissimus)
• tenuitu'ba: from the Latin tuba, "a trumpet" and the prefix tenui- which means "slender or narrow" referring to the flowers (ref. Ipomopsis tenuituba)
• tephro'des: from the Greek tephros for "ash-colored" in reference to the leaves (ref. Helianthus niveus ssp. tephrodes)
• terebinthifo'lius: this is a bit of a puzzle. Terebinthinaceus means pertaining in some way to turpentine, and turpentine (at least the Chian variety) derives from the turpentine tree, Pistacia terebinthus, a member of the sumac family and a native of the Mediterranean region, specifically but perhaps not limited to the island of Chios. So perhaps terebinthifolius means "having leaves like the turpentine tree" (ref. Schinus terebinthifolius)
• terebinth'inus: resembling or appearing like turpentine (ref. Cymopteris terebinthinus)
• te'res: cylindrical, circular in cross-section (ref. Diodia teres)
• tereticor'nis: with terete or cylindrical horns (ref. Eucalyptus tereticornis)
• teretifo'lium/teretifo'lius: terete-leaved, that is, with leaves that are smooth and cylindrical, usually circular in cross-section (ref. Erysimum teretifolium, Chrysothamnus teretifolius)
• terna'ta/terna'tum: with parts in groups of three, referring often to the leaflets (ref. Keckiella ternata, Eriogonum ternatum)
• terna'tea: of the island of Ternate in the Moluccas (ref. Clitoria ternatea)
• tern'ipes: from the Latin terni, "three," and the suffix -pes, referring to the stalk, or foot of something, hence, "three-stalked" (ref. Aristida ternipes)
• terraci'na: uncertain meaning, but possibly having something to do with terraces (?), or a reference to Terracina, a seaside resort area between Rome and Naples, which perhaps makes more sense since this species is originally from the Mediterranean (ref. Euphorbia terracina)
• terres'tris: in Latin means "on land" (ref. Brodiaea terrestris ssp. kernensis, Tribulus terrestris)
• teso'ta: corruption of the Spanish tieso meaning "stiff or firm". Tesota is a southwest Native American name for this tree (ref. Olneya tesota)
• tessella'ta: tessellate or checkered, patterned like a mosaic, in allusion to the arrangement of warts on the back of the nutlets (ref. Amsinckia tessellata)
• testicula'tus: like testicles (ref. Ranunculus testiculatus)
• Tetracoc'cus: "four seeds," from the Greek tetra, "four," and kokkos, "a kernel, grain, or berry," (from Edmund Jaeger's A Source-Book of Biological names and Terms) because of the four-lobed or four-seeded ovary in the original species, T. dioicus.  My original information followed Philip Munz, who used the word kakkos for "fruit," but I have been kindly informed by Dr. Stavros Kakkos of my mistake, and in checking other sources find the proper word source to have been kokkos.  Thank you, Dr. Kakkos. (ref. genus Tetracoccus)
• Tetrady'mia: from the Greek tetra, "four," and dymos, "together," from the four-flowered heads of the first known species of this genus (ref. genus Tetradymia)
• tetrago'na: probably the same as the next entry (ref. Crassula tetragona)
• Tetrago'nia: four-angled (ref. genus Tetragonia)
• tetragonio'ides: like genus Tetragonia (ref. Tetragonia tetragonioides, or literally the Tetragonia that looks like Tetragonia)
• tet'rahit: the Missouri Plants website suggests that this means "four-parted." The name Tetrahit was apparently used as a generic name by French physician and botanist Matthias de l'Obel (1538-1616), but I have no further information on its derivation or meaning (ref. Galeopsis tetrahit)
• tetramer'a/tetramer'es: from tetras, "four," and meris, "part," thus meaning "with four parts (ref. Phacelia tetramera, Tetradymia tetrameres)
• tetrancis'tra: from the Greek tetra, "four," and ankistron, "fish-hook," thus meaning 4 fish-hooks for the 3-4 hooked central spines (ref. Mammillaria tetrancistra)
• Tetraneur'is: from the Greek tetras, "four," and neuron, "nerve" (ref. genus Tetraneuris)
• tetraphyl'lum: four-leaved (ref. Polycarpon tetraphyllum)
• tetrasper'ma: four-seeded (ref. Vicia tetrasperma)
• Teu'crium: there seems to be a lot of confusion about this name, although most of the confusion may be on my part alone. The Jepson Manual simply says an ancient Greek name. The Botanary website says "Named for Teucer, a Trojan king who used the plant as a medicine; or possibly for Dr. Teucer, a botanist and physician." Stearns' Dictionary of Plant Names says: "Possibly named for Teucer, first king of Troy." The Columbia Encyclopedia gives two alternate meanings: "1 Ancestor and king of the Trojans, who are also called the Teucri. He was the father-in-law of Dardanus. 2 Son of Telamon and Hesione. He was the greatest archer in the Trojan War and a faithful comrade of his half brother, the Telamonian Ajax. When he returned home he was banished by his father, who mistakenly thought that Teucer was responsible for the death of Ajax. Teucer went to Cyprus, where he founded the town of Salamis and ruled as king." Umberto Quattrocchi states: "From the Greek teukrion, possibly for Teucer (Teukros), the founder of the town of Salamis in Cyprus." Encyclopedia Mythica says: "Teucer was the son of the river Scamander and the nymph Idaea, and was the legendary ancestor of the Trojans; hence the Trojans are often called 'Teucrians.' He should not be confused with the Teucer who was the son of Telamon and the brother of Ajax, and who fought against Troy during the Trojan War." And Wikipedia states that Teucer was "The son of Hesione and Telamon, Teucer fought with his half-brother, Ajax the Great, in the Trojan War and is the legendary founder of the city Salamis on Cyprus." It appears that there were two separate figures, Teucrus, who was the ancestor of the Trojans, and the Greek Teucer who fought in the Trojan War and founded Salamis. However, another website stated that the Teucer who was the founder ancestor of the Trojans also fought in the Trojan War against the Greeks, and I don't see how that would have been possible. As to which of these figures is honored by the name Teucrium, Pliny wrote that Teucer discovered Teucrium during the same period in which Achilles discovered Achillea, so he would be refering to the one who fought in the Trojan War (ref. genus Teucrium)
• texa'na/texa'num/texa'nus: of or from, or somehow relating to, Texas (ref. Bergia texana, Erodium texanum, Nuttallanthus texanus)
• texen'sis: same as previous entry (ref. Carex retroflexa var. texensis)
• tex'tilis: from the Latin textilis, "woven or braided" (ref. Juncus textilis)
• thacheria'num: after Olive Day Thacher (1891-1971), member of the California Botanical Society, recipient in 1915 of a BS in botany from the University of California, and daughter of Sherman Day Thacher who in 1889 founded the Thacher School in Ojai, which was then known as the School for Out-of-Door Life and Study (ref. Ribes thacherianum)
• thalia'na: after Johannes Thal (1542-1583), who discovered this species in the Harz Mountains and originally called it Pilosella siliquosa. Its current name was finally settled on in his honor in 1842 (ref. Arabidopsis thaliana)
• Thalic'trum: from thaliktron, a name used to describe a plant with divided leaves, and a name given to the genus by Dioscorides, the Greek physician and pharmacologist who wrote the Materia Medica, which remained the leading pharmacological text for sixteen centuries (ref. genus Thalictrum)
• Thamnos'ma: from the Greek for "odorous shrub" (ref. genus Thamnosma)
• -thamnus: a shrub (ref. genera Chrysothamnus, Malacothamnus)
• thap'sus: of Thapsus in ancient Africa (now Tunisia) or of Thapsos in Greece, uncertain (ref. Verbascum thapsus)
• -theca: cover, case, container (ref. genus Heterotheca, also Spergularia macrotheca)
• Thelesper'ma: from the Greek thele, "nipple," and sperma, "seed," and referring to the roughened achenes (ref. genus Thelesperma)
• Thelypo'dium: from the Greek thelys, "female," and pus, "foot," from the presence of the stipe or stalk above the receptacle (ref. genus Thelypodium)
• Thelyp'teris: from the Greek thelys, "female," and pteris, "fern" (ref. genus Thelypteris)
• theophras'ti: named after the Greek philospher and botanist Theophrastos (371-c287 B.C.). The following is quoted from a website called Theophrastus of Eresos: "Around 320 BC the Greek philosopher Theophrastus begins the science of botany with his books De causis plantarum/The Causes of Plants and De historia plantarum/The History of Plants. In them he classifies 500 plants, develops a scientific terminology for describing biological structures, distinguishes between the internal organs and external tissues of plants, and gives the first clear account of plant sexual reproduction, including how to pollinate the date palm by hand. Theophrastus (or Theophrast or Theophrastos) (371 or 372 -287/286) BC, the son of Melantas, born in Eresos on Lesbos, was a student of Aristotle and succeeded him as a director of the Lyceum in Athens. He took over the philosophy of Aristotle in parts reshaping, commenting, and developing it in an original way. His thinking leads to empirism by means of observation, collection, and classification. He was around 35 years the director of the Lyceum and he was a teacher of up to 2000 students. His true name was Tyrtamos of Eresos. Due to his oratory talents he was nicknamed Euphrastos, the well-spoken, eventually to become famous as Theophrastus, divine spoken. Having joined Plato’s Academy at the age of 17 he soon fell to Aristotle’s spell and accompanied him, still a young man, in his self-chosen exile on the Troad then on his home island Lesbos. He then disappeared from the record for three or more years – during which time some believe he traveled far, to Crete and Libya to come again at Aristotle’s side in Stageira. From there on he never again left his master except for his short last exile, succeeding him as the headmaster of the peripatetic school until his death in 287, at the venerable age of 85. He is said to have been a congenial chap, sworn bachelor and gourmet, and to have died of the sequels of the wedding party of one of his pupils. The main innovation of Theophrastus is his attempt to find a connection between the 'first principles' (the intelligible world, ratio) and the perceivable objects of nature; this distinction remains the main motive of occidental philosophy during the next two millenia with different solutions. Theophrastus is also called 'father of botany' and can be regarded as the founder of ecology, too. He described the origin of plants from seeds, he carried out germination experiments, discussed the influence of abiotic habitat factors on plants, the ecology of domestic plants, pollination of plants with the example of the fig, he invented a growth form terminology which is still valid (root, shoot). He described more than 500 species and varieties of plants from lands bordering the Atlantic and Mediterranean. He classified plants into trees, shrubs, under shrubs, and herbs. He noted that some flowers bear petals whereas others do not, and observed the different relative positions of the petals and ovary. In his work on propagation and germination, Theophrastus described the various ways in which specific plants and trees can grow: from seeds, from roots, from pieces torn off, from a branch or twig, or from a small piece of cleft wood." (ref. Abutilon theophrasti)
• therma'le/therma'lis: of warm springs (ref. Gnaphalium canescens ssp. thermale, Phacelia thermalis)
• thermop'ola: David Hollombe at first thought this was for Thermopolis, Wyoming, but then found out that "the type locality was on the Snake River near the southern entrance to Yellowstone and the range was originally thought of as a narrow band from Yellowstone to Salt Lake City, all far to the west of Thermopolis, but I think there is still a reference to hot springs, just different ones." (ref. Artemisia arbuscula ssp. thermopola)
• Thermop'sis: from the Greek thermos for lupine and opsis, "like," bearing yellow lupine-like flower heads (ref. genus Thermopsis)
• Thlas'pi: from the Greek thlaein, "to crush," from the flattened silicle, and the Greek name for a cress (ref. genus Thlaspi)
• thom'asii: after Major George Henry Thomas (1816-1870), stationed at Fort Yuma about 1850, and later as a general a Civil War hero called the Rock of Chickamauga (ref. Eriogonum thomasii)
• thompson'iae: after Ellen Louella Powell Thompson (1843-1911), called "Nellie." She was the sister of John Wesley Powell and having a degree in botany she accompanied her husband, Almon Harris Thompson, on an expedition through the Escalante Wilderness in 1872. Thompson had been appointed by Powell to lead the expedition after he left to return to Salt Lake City to visit his wife and new child. They charted the course of the Escalante River which was the last named river in the United States. At one point the expedition climbed a pass between two peaks: Mt. Ellen and Mt. Pennell. "Prof" Thompson named Mt. Ellen after his wife, "Nellie." She was the first person to do botanical studies in the region. On his expedition of the year before, Powell had named one of his boats the Nellie Powell (ref. Penstemon thompsoniae, Peteria thompsoniae)
• thorn'ei: after Robert Folger Thorne (1920- ), "Bob" to his friends, Professor of Botany Emeritus at Claremont Graduate University and Rancho Santa Ana Botanical Garden, botanist and authority on angiosperm evolution, and former President of Southern California Botanists.
  The following is quoted from the April/May newsletter of the Orange County Chapter CNPS: "He is retired from his position as curator and taxonomist at the Rancho Santa Ana Botanic Garden, although he continues to conduct research. He is a member of the San Diego chapter of CNPS. He continues also as an active member of Southern California Botanists, where he served previously as president, vice-president, and member of the board. As a young man-he is now 84-he served as a B-24 bomber navigator in World War II. During a mission over Austria, his plane was badly shot up. Despite the fact that the plane was riddled with flak, causing a fire in one engine, the crew managed to parachute over the only partisan-held island (Vis) in the Dalmatian chain, now part of Croatia. (Had he landed on any other island, he and his crewmates would have been prisoners of war). But Dr. Thorne’s military career did not end at that point-after the crew was returned to Italy he flew 29 more missions. Dr. Thorne became hooked on botany when he took required science courses at Dartmouth College. Abandoning plans to become a linguist, he went on to earn an M.S. in 1942 and a Ph.D in 1949 from Cornell University. After graduation, he spent thirteen years at the University of Iowa, as an assistant, associate, then full professor. He became friends with Peter Raven (another giant in the field) during a five-month stint as a researcher at the Royal Botanic Gardens at Kew and the British Museum of Natural History in London. Dr. Raven was then the curator at Rancho Santa Ana, and the Garden accepted his recommendation to appoint Dr. Thorne as his successor when the former moved on to Stanford. During his tenure there (from 1962 to 1987), Dr. Thorne was also Professor of Botany at Claremont Graduate School, now Claremont Graduate University. At that time, famed cactologist Lyman Benson was curator of the herbarium at Pomona College. When Dr. Benson retired, the Pomona College collection was donated to Rancho Santa Ana, and Dr. Thorne became curator of the combined collection. Before and during those years, Dr. Thorne traveled extensively while collecting specimens for herbaria. He spent 1½ years in Australia as a Fulbright researcher studying primitive angiosperms in the rain forests of the region, including New Caledonia, New Guinea, and Tasmania. Based on his travels in Mexico, he has prepared a flora of the high country of the Sierra San Pedro Martir and is working on a flora of the California floristic region of northwestern Baja California. His California publications include the Flora of the Santa Ana Mountains and the Flora of the Santa Rosa Plateau (both with Earl Lathrop), the Flora of the Higher Ranges of the Eastern Mojave (with Jim Henrickson and Barry Prigge) and the Flora of Santa Catalina Island. His numerous other works include two chapters written for the voluminous Terrestrial Vegetation of California, treatments of aquatic monocots in the Jepson Manual and many papers on biogeography, vernal pools, other plant communities of California as well as floras of areas in New York, Iowa, Virginia, Georgia, and Florida. Among other awards and honors and memberships Dr. Thorne has received is the Asa Gray Award from the American Society of Plant Taxonomists. He received two Fulbright scholarships and a National Science Foundation Senior Postdoctoral Fellowship while at the University of Iowa. He has been a Fellow of the Linnaean Society of London and was honored with foreign membership in the Royal Society of Denmark." (ref. Eriogonum thornei, Delphinium variegatum ssp. thornei)
• Thu'ja: from the Greek name thuia or thyia, for a kind of juniper or other resinous tree (ref. genus Thuja)
• Thunber'gia: after Carl Peter Thunberg (1743-1828), "...Swedish botanist, a student of Linnaeus who was pursuaded by Dutch lovers of new plants to enter the service of the Dutch East India Company as a doctor and send back plants from Japan to Europe. He travelled in South Africa and Japan and became professor of botany at Uppsala." (from Stearn's Dictionary) (ref. genus Thunbergia)
• thur'beri: named after Dr. George Thurber (1821-1890), called the most accomplished horticulturist in America, and botanist and quartermaster of the Mexican Boundary Survey, 1850-1854. Dr. Thurber was professor of botany and horticulture at Michigan Agricultural College 1859-1863 and editor of the American Agriculturalist from 1863 until his death in 1890 (ref. Centrostegia thurberi, Eriogonum thurberi, Lepidium thurberi, Penstemon thurberi, Petalonyx thurberi, Pilostyles thurberi)
• thurberia'na/thurberia'num: see previous entry (ref. Agrostis thurberiana, Achnatherum thurberianum)
• Thymophyl'la: from the Greek thymos, "thyme," and phyllon, "leaf," meaning "thyme-leaved" (ref. genus Thymophylla)
• thysanocar'phus: like platycarphus, there are two possibilities here: (1) from Greek thusanos, "fringe," and karphos, "a dry splinter, twig, straw," in turn from karpho, "to dry up or wither," referring to the pappus or to the scales of the involucre; (2) it is also possible that this is just an alternate spelling of 'thysanocarpus' meaning "fringed fruit" (ref. Orochaenactis thysanocarphus)
• thyrsiflor'a: with flowers in a thyrse, which according to Harris and Harris's Plant Identification Terminology is "a compact cylindrical or ovate panicle with an indeterminate main axis and cymose sub-axes" (ref. Lysimachia thyrsiflora)
• Thysanocar'pus: from the Greek words thusanos, "fringe," and karpos, "fruit," hence "fringed fruit" (ref. genus Thysanocarpus)
• tiburonen'sis: I think this refers to the town of Tiburon in Marin County (ref. Calochortus tiburonensis)
• Tidestro'mia/tidestro'mii: named for American botanist Ivar (Frederick) Tidestrøm (1864-1956), author of Flora of Utah and Nevada (1925) and Flora of Arizona and New Mexico (1941) with Sister Teresita Kittell. He apparently also did work in Maryland and Virginia (ref. genus Tidestromia, also Astragalus tidestromii, Lupinus tidestromii)
• tiehm'ii: after amateur plant collector and professional bellhop and limo driver Arnold Gerard Tiehm of Reno, Nevada, (1951- ), author of Nevada Vascular Plant Types and Their Collectors, published by the New York Botanical Garden in 1996. Tiehm has had the rare good luck to have discovered nineteen new plants, six of which bear his name, all found on days off in his native Nevada "backyard." He is also the author of a biography of Per Axel Rydberg, and according to David Hollombe, is at work on a biography of Amos Arthur Heller (ref. Arabis tiehmii, Juncus tiehmii)
• tilin'gii: named after Heinrich Sylvester Theodor Tiling (1818-1871), a Baltic physician and botanist for a Russian-American company in Sitka who also collected plants in California and Nevada for various European botanical gardens (ref. Mimulus tilingii)
• tillae'a: for the Italian botanist Michael Angelo Tilli (1655-1740), professor of botany and fellow of the Royal Society of London, author of Catalogus plantarum horti Pisani, and from 1685 until his death Praefectus (the person in charge) of the Botanical Garden of the University of Pisa (ref. Crassula tillaea)
• timor'um: a modern Latin dictionary defines timoris as "fear, alarm, dread; a terror" but I don't know whether this has anything to do with the meaning here. David Hollombe says that this name is from the Latin root timoros or timoreo meaning "to help, lend aid, give succour" but again the application is unclear (ref. Eriogonum grande var. timorum)
• tinctor'ia/tinctor'ius: used in dyeing, and usually used to refer to a plant that when broken exudes some kind of stain (ref. Collinsia tinctoria, Collomia tinctoria, Carthamus tinctorius)
• tinc'tus: colored (ref. Astragalus purshii var. tinctus)
• tingita'nus: of Tangiers, whose ancient name was Tingis (ref. Lathyrus tingitanus)
• tioga'na: the only geographical feature I know of with the name of Tioga is Tioga Pass on the road going into Yosemite National Park from the eastern side, and that is what I think this name refers to since this taxon's range is the High Sierras and the White & Inyo Mts (ref. Carex tiogana, Gentiana newberryi var. tiogana)
• Tiqui'lia: a native South American name for a flower of this genus. I thank San Diego County botanist Michael Simpson for sending me the following from Richardson., T. 1977, Monograph of the genus Tiquilia (Coldenia, sensu lato), Boraginaceae: Ehretioideae, Rhodora 79: 467-572.: "Ruiz and Pavon (1799) described Lithospermum dichotomum,
  which they collected in Peru, and subsequently, Persoon (1805) established the genus Tiquilia to accommodate this taxon, the generic name being derived from the vernacular name, reported
  by Ruiz and Pavon (1799) as "Tiquil-tiquil". It is possible that the cited vernacular name is simply a corruption of the Quechua word for flower, "t'ika" (Pers. comm., Helen Barler. April, 1975; Lira, 1973)." (ref. genus Tiquilia)
• ti'ti: after Frank H. Titus (1850-1908). "Graduated from Medical College of the Pacific, San Francisco, CA, 1876; resident physician of St. Luke's Hospital S.F., 1890-92; Supt. S.F. City & Co. Hospital, 1894-95; proprietor of a S.F. pharmacy, 1896; U.S. Army surgeon in the Philippines 1898-1902 (shortened from Cantelow & Cantelow)." (ref. Astragalus tener var. titi)
• tobi'ra: the Dave's Garden Botanary site says that this is from the Japanese name for this plant, the common name being Japanese pittosporum (ref. Pittosporum tobira)
• Tofield'ia: after Thomas Tofield (1730-1799), a British botanist and civil engineer, "bom at Wilsic Hall near Wadworth (4 miles south of Doncaster) on 18 December, 1730, the only surviving son of Thomas Tofield (1695-1747) and his wife Elizabeth Atkinson. He attended William Burrow's School at Chesterfield and in 1747 went up to Trinity College, Cambridge, taking his B.A. in 1751. Returning to Wilsic, he began an intensive study of the local flora. This activity brought him into contact with William Hudson who in the late 1750's was working on a new British flora based on the Linnean system. Tofield sent him many specimens. In Hudson's classic Flora Anglica (1762), Tofield, along with John Blackstone, was singled out for special acknowledgement. He continued to send botanical data, much of which was included in the enlarged second edition of the Flora (1778)." It appears that botany was only his avocation, his chief interest and occupation being as a hydrological engineer and waterways surveyor, involved mainly with the drainage of various low grounds and the diversion of rivers (ref. genus Tofieldia)
• Tol'miea/tol'miei: named after William Fraser Tolmie (1812-1886), a Scottish physician with the Hudson Bay Company first at Fort Vancouver then elsewhere. He was the first white man to reach the summit of Mount Rainier, now known as Tolmie Peak. He was manager of the Puget Sound Agricultural Company, the HBC's farming subsidiary. He was elected to the House of Assembly of Vancouver Island as member for Victoria in January 1860. He was re-elected in 1863, and remained a member until Vancouver Island was annexed by the mainland colony of British Columbia in 1866. He became involved in education on Vancouver island serving for several years first on the General Board of Education and then as Chairman of the Board. One of his sons, Simon Fraser Tolmie, became the Prime Minister of British Columbia (ref. genus Tolmiea, also Allium tolmiei, Saxifraga tolmiei)
• Tol'pis: Umberto Quattrocchi says, "Origin unknown, possibly from the Greek tolype, 'a ball of wool, lump,' referring to the fruiting capitula [i.e. the small flowering heads]; some suggest from Crepis" (ref. genus Tolpis)
• tomentel'la/tomentel'lus: with small woolly hairs, diminutive of tomentosa, the oak species that bears this name being somewhat tomentose (ref. Frangula californica ssp. tomentella, Quercus tomentella)
• tomento'sa/tomento'sum/tomento'sus: densely covered with matted wool or short hair, tomentose (ref. Amsonia tomentosa, Angelica tomentosa, Arctostaphylos tomentosa, Cassia tomentosa, Lessingia glandulifera var. tomentosa, Opuntia tomentosa, Pickeringia montana var. tomentosa, Phoradendron tomentosum, Ceanothus tomentosus)
• tomentulo'sa: slightly tomentose
• tomp'kinsii: after chemical engineer and photographer Philip W. Tompkins (1873-1972). The following is quoted from the California Academy of Sciences: "Philip Tompkins was born in San Anselmo, California. He graduated from the University of California in 1894. An analytical chemist and chemical engineer, he was a founder of the San Francisco chemical firm of Curtis and Tompkins where he continued to work until two years before his death (on 6 December 1972 in San Anselmo, California.) An avid photographer, he explored Utah, Colorado, and Arizona. Tompkins aided in discovering and recording the "Lost Valley of the Goblins" in Utah (1949). His article, "Goblin Valley, Recent History and Need for Protection" accompanied by many of his photographs of the area appeared in National Parks Magazine (October-December 1954). As an expression of appreciation to the Botany Department of the California Academy of Sciences, and a memorial to Alice Eastwood, he funded the Tompkins, Tehipite Botanical Expedition of the Sierra Nevada, California. An account of this journey was published in Leaflets of Western Botany by John Thomas Howell (1958). Tompkins also assisted in the publication of A Flora of Lassen Volcanic National Park, California (1961). Tompkins was a California Academy of Sciences member (1930) and Academy lecturer (1953 "Sections of South-Central Utah", 1955 "Southern Utah Scenes"). His extensive collection of slides, photographs, and negatives were donated to the Academy Library (1957, 1963)." His photographs also appeared in Mesa Land: The History and Romance of the American Southwest by Anna Wilmarth Ickes (ref. Carex tompkinsii)
• Tonel'la: derivation unknown (ref. genus Tonella)
• Tones'tus: anagram of Stenotus (ref. genus Tonestus)
• ton'sum: smooth
• Toril'is: name used by Adanson in 1763, meaning obscure. Umberto Quattrocchi says "A meaningless name or possibly from toreo "to bore through, to pierce," referring to the prickled fruit (ref. genus Torilis)
• torqua'ta: presumably from the Latin torquatus, "adorned with a necklace" (ref. Eucalyptus torquata)
• Tor'reya/torreya'na: named after John Torrey (1796-1873), a professor of chemistry and one of the giants of North American botany who described hundreds of plants brought or sent back by such explorers as John C. Fremont, William Emory, Charles Wilkes, Joseph Nicollet, Howard Stansbury and Charles Pickering, and sent back east also by the Mexican Boundary Expedition and the Pacific railroad survey expeditions, and who named many California species.  Born in New York, he began observing and collecting plants while still a youth. His father was appointed Fiscal Agent for the State Prison of New York when he was 15, and it was there that he met Amos Eaton, a pioneer in the field of natural science education. Eaton encouraged the boy's natural inclinations in the sciences, and at the age of 21 Torrey was selected to prepare A Catalog of the Plants Growing Within Thirty Miles of New York. A year later, he received a medical degree and opened a practice, although he continued to spend a great deal of his leisure time on botany. He became Professor of Chemistry, Mineralogy and Geology, and also Assistant-Surgeon, at West Point in 1824, and then Chair of Chemistry and Botany at the College of Physicians and Surgeons in New York three years later. At one time he was teaching at Columbia, Princeton and West Point simultaneously. His great contribution was not as a collector, but rather as a taxonomist, and he was the first American to move away from the Linnean system of plant classification.  Using John Lindley's system of arranging plants by families, he became of the first botanists to apply this to a major work, A Compendium of the flora of the northern and middle states. His interest in plants expanded to the Great Plains and the western Rocky Mountains after receiving the collections of Dr. Edwin James, botanist of the Long expedition of 1820. He was appointed State Botanist of New York in 1836 and in 1843 published A Flora of the State of New York. He became the mentor and lifelong friend and colleague of Asa Gray, who came to New York as a young student in the mid-1830s to study under the eminent Torrey and became his chemistry lab assistant. The two men co-authored Flora of North America, a major botanical work that was based at least in part on the descriptions and specimens of new plants sent east by Thomas Nuttall, but which was never completely finished during their lifetimes. His name was given to the Torrey pine in California by plant explorer Charles Parry who first found it.  A year before his death, he visited Parry in the Rocky Mountains of Colorado, and the latter was able to show him not only the peak he had named in Torrey's honor but also many living plants that he had described from dead specimens fifty years before. On that same trip he stayed with his friend George Engelmann in St. Louis and met John Muir in California. He was President of the American Association for the Advancement of Science, and twice President of the New York Lyceum of Natural History. As though all of his other occupations were not enough, he also served as supervisor of the New York Mint, and despite being one of the greatest American botanists, I have read that he never was able to make a living as a botanist, and he always considered that chemistry was his true profession. He founded the Botanical Club of New York which later became the Torrey Botanical Club, and his own collection eventually went to the New York Botanical Garden (ref. genus Torreya, also species Melica torreyana, Pinus torreyana, Suaeda torreyana)
• tor'reyi: see torreyana above (ref. Amaranthus torreyi, Atriplex lentiformis ssp. torreyi, torreyi, Collinsia torreyi var. wrightii, Epilobium torreyi, Juncus torreyi, Lathyrus torreyi, Lomatium torreyi, Lycium torreyi, Malacothrix torreyi, Mentzelia torreyi, Mimulus torreyi, Phyllospadix torreyi, Plagiobothrys torreyi)
• Torreyochlo'a: after botanist John Torrey (1796-1873), see torreyana above (ref. genus Torreyochloa)
• torticul'mis: with twisted stems (ref. Eleocharis torticulmis)
• tortifo'lia: from the Latin for "twisted leaf" (ref. Xylorhiza [formerly Machaeranthera] tortifolia)
• tortil'is: twisted (ref. Camissonia walkeri ssp. tortilis)
• tortuo'sum/tortuosus: winding, very twisted (ref. Jasminum tortuosum, Streptanthus tortuosus)
• tournefor'tii: after Joseph Pitton de Tournefort (1656-1708), author of Institutiones Rei Herbariae published in 1700 and a celebrated French botanist who was the first to properly define genera and was an important forerunner of Linnaeus. He died the year after Linnaeus was born (ref. Brassica tournefortii)
• Townsend'ia: named for David Townsend (1787-1858), an amateur botanist of Pennyslvania (ref. genus Townsendia)
• Toxicoden'dron: means "poison tree" (ref. genus Toxicodendron)
• Toxicoscor'dion: Scott Earle of Larkspur Books provides the following: "Scordion is a Greek word for garlic, thus "poisonous garlic" from the rather remote resemblance of the death camases to Allium sativum," and I thank him for his contribution (ref. genus Toxicoscordion)
• trachycar'pus: from the Greek trachys, "rough," and karpos, "fruit" (ref. Plagiobothrys trachycarpus)
• trachycau'lus: rough-stemmed (ref. Elymus trachycaulus)
• trachygo'num: rough-kneed or rough-joined (ref. Eriogonum trachygonum)
• trachyphyl'la: rough-leaved (ref. Festuca trachyphylla)
• trachysper'ma: from the Greek trachys, "rough," and sperma, "seed" (ref. Polanisia dodecandra ssp. trachysperma)
• tra'cyi/Tracyin'a: after Joseph Prince Tracy (1879-1953), title examiner of Eureka and botanist who amassed a collection of some 50,000 specimens from north-western California and adjacent Oregon which subsequently became part of the University Herbarium of the University of California (ref. Collomia tracyi, Lomatium tracyi, Lupinus tracyi, Penstemon tracyi, Romanzoffia tracyi, Sanicula tracyi, also genus Tracyina)
• Tradescan'tia: after John Tradescant (1608-1662), English gardener to King Charles I (ref. genus Tradescantia)
• Tra'gia: the Latin name of Hieronymus Bock (1498-1554), a German herbalist (ref. genus Tragia)
• Tragopo'gon: derived from two Greek words tragos meaning "goat" and pogon meaning "beard," suggested by its prominent, feathery hairs when in seed (ref. genus Tragopogon)
• tra'gus: possibly from the Greek tragos, a part of the ear, literally "goat," or from Hieronymous Tragus, the Greek name for Jerome Bock (1498-1554), physician, scholar, and one of the three fathers of German botany (ref. Salsola tragus)
• trans-: beyond, through, across
• Transberin'gia: this genus contains a single species with two subspecies, one in northwestern North America and one in northeastern Asia, separated by the Bering Strait, hence 'trans' 'Bering' (ref. genus Transberingia)
• transitor'ius: I am assuming that this means what the modern English word 'transitory' means, that is "of brief duration, not persistent, temporary," but it may alternatively mean "transitional or intermediate" (ref. Rumex salicifolius var. transitorius)
• transmonta'na: beyond the mountains (ref. Gilia transmontana)
• transvalen'sis: of or from the Transvaal Province of South Africa (ref. Cynodon transvalensis)
• transver'sa: transverse, set crosswise, made at right angles (ref. Gilia leptantha ssp. transversa, Piperia transversa)
• trask'ae/trask'iae: after Luella Blanche (Engle) Trask (1865-1916), resident of Catalina Island from 1895 to 1915 and botanical explorer and collector who lost many specimens in the 1906 San Francisco earthquake and fire and a later fire in Avalon on Catalina Island in 1916. Born in Waterloo, Iowa, she moved with her family to Minnesota while still a youngster. Her father was a nurseryman. She seemed to have had a love of flowers from the earliest age, and recalled the story that her mother would find her in the garden at the age of 2 or 3 kissing the pansies and verbenas She studied and collected plants in the southern part of Minnesota, before eventually marrying, having a daughter, and moving to Santa Monica, California. In addition to botany, her interests included archeology, history, zoology and geology, and beyond the Channel Islands she also worked and explored in the deserts of the Southwest, the San Jacinto Mountains, Death Valley, Arizona, Utah, Colorado and Yellowstone. She carried on an extensive correspondence with Alice Eastwood and Willis Jepson. Her winter home was in Avalon, but she also had a summer refuge in Fisherman's Cove, and frequently walked the roundtrip route over the ridge trail in a day. She was described by Charles Frederick Milspaugh, former Curator of the Field Museum of Natural History in Chicago, as an "indefatigable pedestrian" (ref. Astragalus traskiae, Cercocarpus traskiae, Dudleya traskiae, Cryptantha traskiae, Eriodictyon traskiae, Mimulus traskiae)
• Trautvetter'ia: after Ernst Rudolf von Trautvetter (1809-1889), Russian botanist who specialized in the flora of the Caucasus and central Asia and was author of De Echinope genere capita (1833) and the Decas plantarum novarum published in St. Petersburg, 1882 (ref. genus Trautvetteria)
• treleas'ei: after William Trelease (1857-1945), who was "born in Mount Vernon, New York in 1857. In his teens he was briefly apprenticed in a machine shop, but in 1877 he decided to enter Cornell College and study the natural sciences. After Cornell, he taught at the University of Wisconsin, and planned to study bacteriology there; but when he was offered the director's job at the St. Louis Botanical Garden, he accepted. It was an ideal position for Trelease, a gifted botanist with a genius for classifying plants. He directed the 75 acre garden for 23 years, during which time he identified and named 2500 species and varieties of flora. Trelease's botanical interests were broad: he published a paper on the giant cactus of Mexico in the same year that he published his findings about coastal species in Alaska. He studied apple scab, leaf blight, nematodes. [In 1899 he joined John Muir on the Harriman Alaska expedition aboard the ship Elder.] While on the Elder, he worked with the others involved in botany, collecting specimens, but tending to play second fiddle to Muir, Gilbert and the other, more talkative, scientists. He was first and foremost a scientist, not a story-teller. After the expedition, he returned to St. Louis, and eventually taught at the University of Illinois. His work includes hundreds of scholarly papers, but Trelease was not solely an academic. He published a small, inexpensive set of guides for the everyday gardener, that remain, to this day, a value for anyone who wishes to graft an apple tree, or identify and avoid poison ivy in the winter. Trelease died in 1945." He was the author of Winter Botany: An Identification Guide to Native Trees & Shrubs and his name is on Mt. Trelease in Colorado (ref. Draba paysonii var. treleasei, Opuntia basilaris var. treleasei)
  
• trem'ula: trembling, referring to foliage
• tremulo'ides: like the quivering poplar or quaking aspen (ref. Populus tremuloides)
• tri-: in compound words signifying three
• triacan'thos: three-spined (ref. Gleditsea triacanthos)
• triangular'is: with three angles (ref. Atriplex triangularis, Pentagramma triangularis, Senecio triangularis)
• triangulival'vis: presumably with one or more three-angled or triangular valves (ref. Rumex triangulivalvis)
• Trian'tha: probably the same as Trianthema, that is, three-flowered (ref. genus Triantha)
• Trianth'ema: from the Greek treis, "three," and anthemon, "flower" (ref. genus Trianthema)
• Tribo'lium: from the Greek name tribolos applied to various prickly plants (ref. genus Tribolium)
• tribractea'tum: three-bracted (ref. Allium tribracteatum, Lythrum tribracteatum)
• Trib'ulus: from the Greek tribeles or tribolos and Latin tribulus for "three-pointed, a caltrop," the shape of which is suggested by the three-pronged fruit, and referring to the caltrop, an ancient military weapon which consisted of an iron ball with projecting spikes that could be strewn on the battlefield to impede cavalry or foot soldiers. At least one spike projected upwards while others anchored the caltrop in the ground (ref. genus Tribulus)
• Tricar'dia: from the Greek tri for "three" and cardia for "heart," thus "three-hearted," apparently from the structure of the calyx (ref. genus Tricardia)
• tricarinat'us: three-keeled, or by extension, three-ribbed or with three angled sides (ref. Astragalus tricarinatus)
• tri'ceps: three-headed
• trichan'tha: three-flowered (ref. Zeltnedra trichantha)
• tricho-: in compound words signifying hairy or hair-like
• trichoca'lyx: with a hairy calyx (ref. Eriodictyon trichocalyx var. lanatum, Eriodictyon trichocalyx var. trichocalyx, Romneya trichocalyx)
• trichan'thum: hairy-flowered (ref. Centaurium trichanthum)
• trichocar'pa: hairy-fruited (ref. Populus balsamifera ssp. trichocarpa)
• Trichocoron'is: from the Greek trichos, "hair," and koronis, "crown" referring to the pappus (ref. genus Trichocoronis)
• trichoma'nes: the name of a fern mentioned by Theophrastus and Dioscorides, and used by Pliny for a fern resembling Adiantum
• tricho'pes: hairy-footed or -stalked (ref. Eriogonum trichopes)
• Trichophor'um: from the Greek thrix or trichos, "hair," and phoros, "bearing, carrying," referring to the margins of the clinandrum, which is the portion of an orchid column which conceals the anther (ref. genus Trichophorum)
• trichopo'dus: having a hairy pod (ref. Astragalus trichopodus var. lonchus, Astragalus trichopodus var. phoxus)
• Trichoptil'ium: from the Greek trichos, "hair," and ptilon, "feather," in allusion to the dissected pappus-paleae, i.e. the chafflike scales on the receptacle (ref. genus Trichoptilium incisum)
• Trichos'tema: from trichos, "hair," and stema, "stamens," and alluding to the hair-like stamens (ref. genus Trichostema)
• tri'color: of three colors (ref. Gilia tricolor, Verbena tricolor)
• tricorna'tum: three-horned (ref. Galium tricornatum)
• tricuspida'ta: three-pointed
• tricus'pis: probably meaning the same as the above (ref. Mentzelia tricuspis)
• tridactylo'sa: from tri-, "three," and daktylos, "a finger, toe," thus meaning three-fingered or three-toed (ref. Calystegia collina ssp. tridactylosa)
• Tri'dens: three-toothed (ref. genus Tridens)
• tridenta'ta/tridenta'tum: three-toothed (ref. Artemisia tridentata ssp. tridentata, Artemisia tridentata ssp. vaseyana, Larrea tridentata, Mentzelia tridentata, Purshia tridentata var. glandulosa, Trifolium tridentatum)
• Trienta'lis: one-third of a foot in height, about the height of these small plants (ref. genus Trientalis)
• tri'fida/tri'fidum: cleft into three parts (ref. Ambrosia trifida, Bouteloua trifida, Corallorhiza trifida, Galium trifidum var. pusillum)
• triflor'um: three-flowered (ref. Galium triflorum, Solanum triflorum)
• trifolia'ta: three-leaved (ref. Menyanthes trifoliata)
• Trifo'lium: from the Latin meaning "three-leaved" (ref. genus Trifolium)
• trifor'mis: Engelmann described the species as having three varieties: var stylosus ('planta major...'), var. brachystylus ('planta minor...') and var. uniflorus ('planta minima...') (ref. Juncus triformis)
• trifur'ca: thrice forked (ref. Ephedra trifurca)
• triglochidia'tus: with three barbed bristles (ref. Echinocereus triglochidiatus)
• Triglo'chin: from the Greek tri, "three," and glochis, "a point," referring to the fruit of some species (ref. genus Triglochin)
• Trigonel'la: a diminutive of the Latin trigonum, "triangle or three-cornered," referring to the corolla of one of the species (ref. genus Trigonella)
• trigonophyl'la: possibly from trigonus, "three-cornered," and phyllon, "leaf" (ref. Nicotiana trigonophylla)
• trigy'na/trigyn'um: with three pistils (ref. Linum trigynum)
• trilliifo'lia: with leaves like genus Trillium (ref. Oxalis trilliifolia)
• trilo'ba/trilo'bata: indicates leaves are three-lobed (ref. Ipomoea triloba, Oxytheca trilobata)
• trimes'tris: blooming for three months (ref. Lavatera trimestris)
• Trimor'pha: from the Greek treis or tria, "three," and morphe, "a shape," in reference to the flower types (ref. genus Trimorpha)
• triner'via: with three nerves or veins (ref. Flaveria trinervia)
• trin'ii: after Karl Bernhard von Trinius (1778-1844), Russian court physician and world-famous agrostologist who was born in Germany (ref. Bromus trinii)
• triniten'sis: of or from the area of the Trinity Mountains of northern California (ref. Arctostaphylos trinitensis)
• tri'odon: from the Greek for "three" and "tooth," referring to the three lobes of the petals (ref. Aliciella triodon)
• Triodan'us: from Greek treis, "three," and odons, "tooth," hence "three-toothed" (ref. genus Triodanus)
• trio'num: Jaeger's Source-book of Biological Names and Terms gives two alternate etymologies for this name: (1) from New Latin trionum derived from the Greek trionon, the name of a malvaceous plant; and (2) from Latin Triones, referring to Ursa Major or the Big Dipper. "Ursa Major in English tradition is the Plough derived possibly from the Triones or Teriones, the Plough Oxen or Threshing Oxen of Roman fable; Cicero mentions them as the Septentriones, which later became a term for the north wind, the northern heavens and polar things in general." (From a website on Ursa Major) Since this plant is malvaceous and not particular polar or northern, the former etymology is probably correct (ref. Hibiscus trionum)
• tripar'tita: in three parts, having three parts (ref. Bidens tripartita)
• triphyl'la: three-leaved (ref. Achlys triphylla, Lewisia triphylla)
• triphyl'los: probably same as previous entry (ref. Veronica triphyllos)
• Triphysar'ia: from the Greek meaning "having three bladders" because of the lower lip pouches (ref. genus Triphysaria)
• Tripleurosper'mum: from the Greek treis, "three," pleura or pleuron, "rib," and sperma, "seed," referring to the achenes (ref. Tripleurospermum)
• tripo'dum: three-footed (ref. Eriogonum tripodum)
• Tripteroca'lyx: from the Greek tripteros, "three-winged," and kalyx, "calyx" (ref. genus Tripterocalyx)
• triquet'ra/triquet'rum: from the Latin triquetrus meaning "having three corners, triangular" (ref. Boerhavia triquetra, Carex triquetra, Allium triquetrum)
• trisep'alus: with three sepals (ref. Ranunculus bonariensis var. trisepalus)
• Triset'um: from tri, "three," and seta, "bristle, hair," referring to the three awns on the lemmas (ref. genus Trisetum)
• trista'chya: three-spiked (ref. Eleusine tristachya)
• tris'te: dull, sad (ref. Hieracium triste)
• tris'tulis: diminutive of tristis, "sad" (ref. Fritillaria affinis var. tristulis)
• trisul'ca: with three furrows (ref. Lemna trisulca)
• Tritel'eia: from the Greek tri, "three," and teleios, "perfect," the floral parts being in 3's (ref. genus Triteleia)
• triterna'tum: triply ternate (ref. Lomatium triternatum)
• tritico'ides: like genus Triticum, or wheat (ref. Leymus triticoides)
• Trit'icum: the classical Latin name for wheat (ref. genus Triticum)
• triuncia'lis: the Latin uncia means one-twelfth, so this might mean three-twelfths, of unknown application (ref. Aegilops triuncialis)
• trivia'le/trivia'lis: common, ordinary (ref. Alisma triviale, Poa trivialis)
• trixa'go: Brown's Composition of Scientific Words says that this name is Latin for germander, but then -ago is a Latin substantival suffix used to indicate a resemblance or property, and trix could derive from trix (thrix), "a hair," or trixos "three-fold," inasmuch as B. trixago is a glandular-hairy plant, and it was apparently an old name for some plant possibly of the mint family (ref. Bellardia trixago)
• Trix'is: from the Greek trixos, "three-fold," referring to the three-cleft outer corolla lip (ref. genus Trixis)
• trochlear'is: from the Greek trochlea, "a pulley," plus -aris, "belonging or pertaining to," of uncertain application (ref. Callitriche trochlearis)
• trolliifo'lium: with leaves like genus Trollius in the buttercup family (ref. Delphinium trolliifolium)
• Tropaeo'lum: the nasturtium of gardeners, although not of botanists, and named by Linnaeus, from the Greek tropaion and the Latin tropaeum for "trophy," the manner in which the plant grew up a support reminding him of a classical trophy with round shields and golden helmets such as those hung as a sign of victory on a battlefield (ref. genus Tropaeolum)
• Tropidocar'pum: from the Greek meaning "keel fruit," referring to the keeled capsular valves (ref. genus Tropidocarpum)
• troximo'ides: Jaeger's Sourcebook relates the root trox with trog, from the Greek trogo, "to gnaw" and trogos, "a gnawer, weevil", and Brown's Composition of Scientific Words says that troxalis is the Latin word for grasshopper or cricket, which are gnawing insects. Another piece of evidence for this interpretation is a web listing that I found of the species Microseris troximoides (synonym for Nothocalais troximoides) for which the common name weevil microseris is given (ref. Nothocalais troximoides)
• tru'ei: after Gordon Haines True, Jr. (1908-1984), son of livestock scientist and Professor of Animal Husbandry at UC Davis. True, Jr. graduated from Davis with a degree in Animal Science and received his MS in parasitology from Berkeley in 1931. He first worked as a parasitologist for the California State Department of Fish and Game and then the Bureau of Game Conservation in San Francisco until 1946. After being injured in a car accident, he moved to Nevada to work a dairy ranch and collect local plants. He moved back to California in 1963, two years later becoming a Research Associate in the Botany Department at the California Academy of Sciences (ref. Arctostaphylos mewukka ssp. truei)
• trunca'ta/trunca'tum/trunca'tus: abruptly cut off (ref. Atriplex truncata, Horkelia truncata, Pellaea truncata, Lupinus truncatus)
• truxillen'sis: apparently a reference to the city of Trujillo in Peru, since C. truxillensis was first described from Peru. Trujillo lies on the Pan-American Highway NNW of Lima, in the coastal desert region of the Moche River Valley, and is a commercial, educational, cultural and transportation center. It is the 2nd oldest Spanish city in Peru and was founded in 1534 by Diego de Almagro and elevated to city status the following year by Francisco Pizarro who named it after his birthplace in Spain. Trujillo was visited by Alexander von Humboldt during his epic excursion across Central and South America (1799-1804) in the course of which he travelled some 6000 miles on foot and horseback and by canoe. (ref. Cressa truxillensis)
• Tsu'ga: from a Japanese name for their native hemlocks (ref. genus Tsuga)
• tsugen'se: of hemlocks (ref. Arceuthobium tsugense)
• tu'berans/tuberas'cens: becoming swollen or tuberous
• Tuberar'ia: from the thickened, tuber-like swellings on the roots of the type species (ref. genus Tuberaria)
• tubero'sa: tuberous, alluding to the fact that the rhizomes of some species have tubers (ref. Anemone tuberosa, Sanicula tuberosa, Scutellaria tuberosa)
• tubiflor'a: with tubular flowers
• tubulo'sa: tubular, pipe-like (ref. Swertia tubulosa)
• Tuctor'ia: apparently an anagram of the genus name Orcuttia (ref. genus Tuctoria)
• tularen'se/tularen'sis: of or from the Tulare area of the San Joaquin Valley (ref. Ribes tularense, Atriplex tularensis)
• Tul'ipa: Latinized version of the Turkish tulbend, a turban (ref. genus Tulipa)
• tumes'cens: swollen (ref. Arctostaphylos parryana ssp. tumescens)
• tumulico'la: a dweller of mounds and hillocks (ref. Carex tumulicola)
• tumulo'sa: from the Latin tumulus, "a mound or hillock," and meaning "swollen" (ref. Cryptantha tumulosa)
• tuolumnen'se: from Tuolumne County (ref. Allium tuolumnense)
• turbina'ta: shaped like a spinning top (ref. Abronia turbinata)
• turbinel'la: may mean the same as turbinata (see above) although possibly in diminutive form (ref. Quercus turbinella)
• turionif'era: bearing turions, which are small shoots or buds (ref. Lemna turionifera)
• Turric'ula: Latin for "little tower" (ref. genus Turricula)
• Twisselmann'ia/twisselmann'ii: after Ernest Christian Twisselmann (1917-1972), cattle rancher, authority on southern San Joaquin Valley flora, and author of The Flora of Kern County (ref. genus Twisselmannia, also Nemacladus twisselmannii)
• Ty'pha: the Greek name for this plant (ref. genus Typha)