| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| TRTR5 | Triticum triunciale (L.) Raspail | Aegilops triuncialis | Poaceae
|
| TRTU3 | Triticum turanicum Jakubz. | oriental wheat | Poaceae
|
| TRTU2 | Triticum turgidum L. | rivet wheat | Poaceae
|
| TRUR3 | Triticum urartu Thumanian ex Gandilyan | wheat | Poaceae
|
| TRVA4 | Triticum vaillantianum Wulfen & Schreb. | Elymus repens | Poaceae
|
| TRVA5 | Triticum vavilovii Jakubz. | Vavilov's wheat | Poaceae
|
| TRVU | Triticum vulgare Vill. | Triticum aestivum | Poaceae
|
| TRZH | Triticum zhukovskyi Menabde & Ericzjan | Zhukovsky's wheat | Poaceae
|
| TRITI | Triticum L. | wheat | Poaceae
|
| TREX4 | Tritomaria exsecta (Schrad.) Loeske | | Jungermanniaceae
|
| TREXA | Tritomaria exsectiformis (Breidl.) Loeske ssp. arctica R. M. Schust. | | Jungermanniaceae
|
| TREXE | Tritomaria exsectiformis (Breidl.) Loeske ssp. exsectiformis | | Jungermanniaceae
|
| TREX3 | Tritomaria exsectiformis (Breidl.) Loeske | | Jungermanniaceae
|
| TRHE9 | Tritomaria heterophylla R. M. Schust. | | Jungermanniaceae
|
| TRPOP | Tritomaria polita (Nees) J�rg. ssp. polita | | Jungermanniaceae
|
| TRPOP2 | Tritomaria polita (Nees) J�rg. ssp. polymorpha R. M. Schust. | | Jungermanniaceae
|
| TRPO13 | Tritomaria polita (Nees) J�rg. | | Jungermanniaceae
|
| TRQUG | Tritomaria quinquedentata (Huds.) H. Buch ssp. quinquedentata var. grandiretis H. Buch & S. W. Arnell | | Jungermanniaceae
|
| TRQUQ | Tritomaria quinquedentata (Huds.) H. Buch ssp. quinquedentata var. quinquedentata | | Jungermanniaceae
|
| TRQUQ2 | Tritomaria quinquedentata (Huds.) H. Buch ssp. quinquedentata | | Jungermanniaceae
|
| TRQUT | Tritomaria quinquedentata (Huds.) H. Buch ssp. turgida (Lindb.) Damsh. | | Jungermanniaceae
|
| TRQU | Tritomaria quinquedentata (Huds.) H. Buch | | Jungermanniaceae
|
| TRSC10 | Tritomaria scitula (Taylor) J�rg. | | Jungermanniaceae
|
| TRITO2 | Tritomaria Schiffn. ex Loeske | | Jungermanniaceae
|
| TRCR8 | Tritonia �crocosmiiflora (V. Lemoine) Nichols. | Crocosmia crocosmiiflora | Iridaceae
|
| TRBA6 | Triumfetta bartramia L. | Triumfetta rhomboidea | Tiliaceae
|
| TRBO5 | Triumfetta bogotensis DC. | parquet burr | Tiliaceae
|
| TRCO14 | Triumfetta cordifolia A. Rich. | cordleaf burrbark | Tiliaceae
|
| TREX | Triumfetta excisa Urban | Triumfetta rhomboidea | Tiliaceae
|
| TRLA19 | Triumfetta lappula L. | grandcousin | Tiliaceae
|
| TRPE11 | Triumfetta pentandra A. Rich. | fivestamen burrbark | Tiliaceae
|
| TRRH | Triumfetta rhomboidea Jacq. | diamond burrbark | Tiliaceae
|
| TRSE4 | Triumfetta semitriloba Jacq. | Sacramento burrbark | Tiliaceae
|
| TRTO3 | Triumfetta tomentosa Bojer | tomentose burrbark | Tiliaceae
|
| TRIUM | Triumfetta L. | triumfetta | Tiliaceae
|
| TRCA8 | Trixis californica Kellogg | American threefold | Asteraceae
|
| TRIN6 | Trixis inula Crantz | tropical threefold | Asteraceae
|
| TRRA7 | Trixis radialis (L.) Kuntze | Trixis inula | Asteraceae
|
| TRIXI | Trixis P. Br. | threefold | Asteraceae
|
| TRAL8 | Trollius albiflorus (Gray) Rydb. | Trollius laxus ssp. albiflorus | Ranunculaceae
|
| TRLAA2 | Trollius laxus Salisb. ssp. albiflorus (Gray) A.& D. L�ve & Kapoor | American globeflower | Ranunculaceae
|
| TRLAL | Trollius laxus Salisb. ssp. laxus | American globeflower | Ranunculaceae
|
| TRLAA | Trollius laxus Salisb. var. albiflorus Gray | Trollius laxus ssp. albiflorus | Ranunculaceae
|
| TRLA14 | Trollius laxus Salisb. | American globeflower | Ranunculaceae
|
| TRRI5 | Trollius riederianus Fisch. & C.A. Mey. | Kamchatka globeflower | Ranunculaceae
|
| TROLL | Trollius L. | globeflower | Ranunculaceae
|
| TRAR8 | Trommsdorffia argentea Mart. | Iresine argentata | Amaranthaceae
|
| TRMA7 | Tropaeolum majus L. | nasturtium | Tropaeolaceae
|
| TRMI13 | Tropaeolum minus L. | dwarf nasturtium | Tropaeolaceae
|
| TRPE18 | Tropaeolum peltophorum Benth. | shield nasturtium | Tropaeolaceae
|
| TRTU4 | Tropaeolum tuberosum Ruiz & Pavon | anu | Tropaeolaceae
|
| TROPA | Tropaeolum L. | nasturtium | Tropaeolaceae
|
| TRRA4 | Trophis racemosa (L.) Urban | white ramoon | Moraceae
|
| TROPH | Trophis P. Br. | trophis | Moraceae
|
| TRPO5 | Tropidia polystachya (Sw.) Ames | young palm orchid | Orchidaceae
|
| TROPI2 | Tropidia Lindl. | tropidia | Orchidaceae
|
| TRCA9 | Tropidocarpum capparideum Greene | caperfruit tropidocarpum | Brassicaceae
|
| TRGRD | Tropidocarpum gracile Hook. var. dubium (A. Davids.) Jepson | Tropidocarpum gracile | Brassicaceae
|
| TRGR5 | Tropidocarpum gracile Hook. | dobie pod | Brassicaceae
|
| TROPI | Tropidocarpum Hook. | tropidocarpum | Brassicaceae
|
| TRAP2 | Troximon apargioides Less. | Agoseris apargioides var. apargioides | Asteraceae
|
| TRAU8 | Troximon aurantiacum Hook. | Agoseris aurantiaca var. aurantiaca | Asteraceae
|
| TRGLD | Troximon glaucum Pursh var. dasycephalum Torr. & Gray | Agoseris glauca var. dasycephala | Asteraceae
|
| TRGL7 | Troximon glaucum Pursh | Agoseris glauca var. glauca | Asteraceae
|
| TRGR13 | Troximon grandiflorum Nutt. | Agoseris grandiflora | Asteraceae
|
| TRPA12 | Troximon parviflorum Nutt. | Agoseris glauca var. laciniata | Asteraceae
|
| TRSA7 | Truellum sagittatum (L.) Soj�k | Polygonum sagittatum | Polygonaceae
|
| TRAE3 | Trypethelium aeneum (Eschw.) Zahlbr. | | Trypetheliaceae
|
| TRAN13 | Trypethelium annulare (Fee) Mont. | Trypethelium floridanum | Trypetheliaceae
|
| TRCA29 | Trypethelium carolinianum (Tuck.) R. C. Harris | Bathelium carolinianum | Trypetheliaceae
|
| TRCA23 | Trypethelium catervarium (Fee) Tuck. | Astrothelium variolosum | Trypetheliaceae
|
| TRCA22 | Trypethelium catervarium auct. | Trypethelium nitidiusculum | Trypetheliaceae
|
| TREL11 | Trypethelium eluteriae Sprengel | | Trypetheliaceae
|
| TREX2 | Trypethelium exocanthum Tuck. | Trypethelium virens | Trypetheliaceae
|
| TRFL12 | Trypethelium floridanum (Zahlbr. ex Choisy) R. C. Harris | | Trypetheliaceae
|
| TRMA13 | Trypethelium mastoideum (Ach.) Ach. | | Trypetheliaceae
|
| TRNI4 | Trypethelium nitidiusculum (Nyl.) R. C. Harris | | Trypetheliaceae
|
| TROC4 | Trypethelium ochroleucum (Eschw.) Nyl. | | Trypetheliaceae
|
| TRPA17 | Trypethelium pallescens Fee | Trypethelium ochroleucum | Trypetheliaceae
|
| TRSC6 | Trypethelium scorites Tuck. | Trypethelium virens | Trypetheliaceae
|
| TRSU11 | Trypethelium subeluteriae Makhija & Patwardhan | | Trypetheliaceae
|
| TRTR12 | Trypethelium tropicum (Ach.) Mull. Arg. | | Trypetheliaceae
|
| TRVA8 | Trypethelium variolosum Ach. | | Trypetheliaceae
|
| TRVI9 | Trypethelium virens Tuck. ex Michener | | Trypetheliaceae
|
| TRYPE | Trypethelium Sprengel | trypethelium | Trypetheliaceae
|
| TRRU3 | Tryphane rubella (Wahlenb.) Reichenb. | Minuartia rubella | Caryophyllaceae
|
| TSCA | Tsuga canadensis (L.) Carr. | eastern hemlock | Pinaceae
|
| TSCA2 | Tsuga caroliniana Engelm. | Carolina hemlock | Pinaceae
|
| TSHE | Tsuga heterophylla (Raf.) Sarg. | western hemlock | Pinaceae
|
| TSJE | Tsuga �jeffreyi (Henry) Henry | | Pinaceae
|
| TSME | Tsuga mertensiana (Bong.) Carr. | mountain hemlock | Pinaceae
|
| TSUGA | Tsuga Carr. | hemlock | Pinaceae
|
| TUGU | Tuberaria guttata (L.) Fourr. | European frostweed | Cistaceae
|
| TUBER | Tuberaria (Dunal) Spach | tuberaria | Cistaceae
|
| TUAC | Tubiflora acuminata Small | Elytraria bromoides | Acanthaceae
|
| TUAN2 | Tubiflora angustifolia (Fern.) Small | Elytraria caroliniensis var. angustifolia | Acanthaceae
|
| TUCA | Tubiflora caroliniensis J.F. Gmel. | Elytraria caroliniensis var. caroliniensis | Acanthaceae
|
| TUGI | Tuckermannia gigantea (Kellogg) M.E. Jones | Coreopsis gigantea | Asteraceae
|
| TUMA2 | Tuckermannia maritima Nutt. | Coreopsis maritima | Asteraceae
|
| TUAM | Tuckermannopsis americana (Sprengel) Hale | | Parmeliaceae
|
| TUAU | Tuckermannopsis aurescens (Tuck.) Hale | Ahtiana aurescens | Parmeliaceae
|