| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| THGI2 | Thyrea girardii (Durieu & Mont.) Bagl. & Carestia | | Lichinaceae
|
| THNI2 | Thyrea nigritella Lettau | Lichinella nigritella | Lichinaceae
|
| THPU8 | Thyrea pulvinata (Schaerer) A. Massal. | | Lichinaceae
|
| THPU10 | Thyrea pulvinata auct. | Thyrea confusa | Lichinaceae
|
| THPY2 | Thyrea pyrenoides (Nyl.) Fink | Paulia pyrenoides | Lichinaceae
|
| THYRE | Thyrea A. Massal. | thyrea | Lichinaceae
|
| THCU3 | Thyrsacanthus cuspidatus Nees | Odontonema cuspidatum | Acanthaceae
|
| THST5 | Thyrsacanthus strictus Nees | Odontonema tubiforme | Acanthaceae
|
| THFI2 | Thysanella fimbriata (Ell.) Gray | Polygonella fimbriata | Polygonaceae
|
| THRO3 | Thysanella robusta Small | Polygonella robusta | Polygonaceae
|
| THAM | Thysanocarpus amplectens Greene | Thysanocarpus curvipes | Brassicaceae
|
| THCO9 | Thysanocarpus conchuliferus Greene | Santa Cruz Island fringepod | Brassicaceae
|
| THCUE | Thysanocarpus curvipes Hook. var. elegans (Fisch. & C.A. Mey.) B.L. Robins. | Thysanocarpus curvipes | Brassicaceae
|
| THCUE2 | Thysanocarpus curvipes Hook. var. eradiatus Jepson | Thysanocarpus curvipes | Brassicaceae
|
| THCUL | Thysanocarpus curvipes Hook. var. longistylus Jepson | Thysanocarpus curvipes | Brassicaceae
|
| THCU | Thysanocarpus curvipes Hook. | sand fringepod | Brassicaceae
|
| THEL3 | Thysanocarpus elegans Fisch. & C.A. Mey. | Thysanocarpus curvipes | Brassicaceae
|
| THLAD2 | Thysanocarpus laciniatus Nutt. ssp. desertorum (Heller) Abrams | Thysanocarpus laciniatus | Brassicaceae
|
| THLAC | Thysanocarpus laciniatus Nutt. var. conchuliferus (Greene) Jepson | Thysanocarpus conchuliferus | Brassicaceae
|
| THLAC2 | Thysanocarpus laciniatus Nutt. var. crenatus (Nutt.) Brewer | Thysanocarpus laciniatus | Brassicaceae
|
| THLAE | Thysanocarpus laciniatus Nutt. var. emarginatus (Greene) Jepson | Thysanocarpus laciniatus | Brassicaceae
|
| THLAH | Thysanocarpus laciniatus Nutt. var. hitchcockii Munz | Thysanocarpus laciniatus | Brassicaceae
|
| THLAR | Thysanocarpus laciniatus Nutt. var. ramosus (Greene) Munz | Thysanocarpus laciniatus | Brassicaceae
|
| THLAR2 | Thysanocarpus laciniatus Nutt. var. rigidus Munz | Thysanocarpus laciniatus | Brassicaceae
|
| THLA3 | Thysanocarpus laciniatus Nutt. | mountain fringepod | Brassicaceae
|
| THPU6 | Thysanocarpus pusillus Hook. | Athysanus pusillus | Brassicaceae
|
| THRA | Thysanocarpus radians Benth. | ribbed fringepod | Brassicaceae
|
| THYSA | Thysanocarpus Hook. | fringepod | Brassicaceae
|
| TICA5 | Tiarella californica (Kellogg) Rydb. | Tiarella trifoliata var. laciniata | Saxifragaceae
|
| TICOA | Tiarella cordifolia L. var. austrina Lakela | heartleaf foamflower | Saxifragaceae
|
| TICOC | Tiarella cordifolia L. var. collina Wherry | heartleaf foamflower | Saxifragaceae
|
| TICOC2 | Tiarella cordifolia L. var. cordifolia | heartleaf foamflower | Saxifragaceae
|
| TICO | Tiarella cordifolia L. | heartleaf foamflower | Saxifragaceae
|
| TILA4 | Tiarella laciniata Hook. | Tiarella trifoliata var. laciniata | Saxifragaceae
|
| TIMA3 | Tiarella macrophylla Small p.p. | Tiarella cordifolia var. cordifolia | Saxifragaceae
|
| TIME2 | Tiarella menziesii Pursh | Tolmiea menziesii | Saxifragaceae
|
| TITRU2 | Tiarella trifoliata L. ssp. unifoliata (Hook.) Kern | Tiarella trifoliata var. unifoliata | Saxifragaceae
|
| TITRL | Tiarella trifoliata L. var. laciniata (Hook.) Wheelock | threeleaf foamflower | Saxifragaceae
|
| TITRT | Tiarella trifoliata L. var. trifoliata | threeleaf foamflower | Saxifragaceae
|
| TITRU | Tiarella trifoliata L. var. unifoliata (Hook.) Kurtz | oneleaf foamflower | Saxifragaceae
|
| TITR | Tiarella trifoliata L. | threeleaf foamflower | Saxifragaceae
|
| TIUN3 | Tiarella unifoliata Hook. | Tiarella trifoliata var. unifoliata | Saxifragaceae
|
| TIWH | Tiarella wherryi Lakela | Tiarella cordifolia var. collina | Saxifragaceae
|
| TIARE | Tiarella L. | foamflower | Saxifragaceae
|
| TIIN | Tiaridium indicum (L.) Lehm. | Heliotropium indicum | Boraginaceae
|
| TIGR3 | Tibouchina granulosa (Desr.) Cogn. | | Melastomataceae
|
| TIHE2 | Tibouchina herbacea (DC.) Cogn. | herbaceous glorytree | Melastomataceae
|
| TIHE4 | Tibouchina heteromalla Cogn. | silverleafed princess flower | Melastomataceae
|
| TILA7 | Tibouchina laxa (Desr.) Cogn. | | Melastomataceae
|
| TILO | Tibouchina longifolia (Vahl) Baill. ex Cogn. | longleaf glorytree | Melastomataceae
|
| TISE2 | Tibouchina semidecondra (Schrank & Mart. ex DC.) Cogn. | purple glory tree | Melastomataceae
|
| TIUR | Tibouchina urvilleana (DC.) Cogn. | princess-flower | Melastomataceae
|
| TIBOU | Tibouchina Aubl. | glorytree | Melastomataceae
|
| TINU | Ticanto nuga (L.) Medik. | gray nicker | Fabaceae
|
| TICAN2 | Ticanto Adans. | gray nicker | Fabaceae
|
| TIPY | Tichothecium pygmaeum Korber | Muellerella pygmaea | Verrucariaceae
|
| TIZA | Tichothecium zahlbrucknerella Henssen | Endococcus zahlbrucknerellae | Uncertain Lichen Family
|
| TICA2 | Tidestromia carnosa (Steyermark) I.M. Johnston | fleshy honeysweet | Amaranthaceae
|
| TIGE | Tidestromia gemmata I.M. Johnston | TransPecos honeysweet | Amaranthaceae
|
| TILAC | Tidestromia lanuginosa (Nutt.) Standl. var. carnosa (Steyermark) Cory | Tidestromia carnosa | Amaranthaceae
|
| TILA2 | Tidestromia lanuginosa (Nutt.) Standl. | woolly tidestromia | Amaranthaceae
|
| TIOB | Tidestromia oblongifolia (S. Wats.) Standl. | Arizona honeysweet | Amaranthaceae
|
| TISU | Tidestromia suffruticosa (Torr.) Standl. | shrubby honeysweet | Amaranthaceae
|
| TIDES | Tidestromia Standl. | honeysweet | Amaranthaceae
|
| TIGR4 | Tigridia grandiflora Diels | peacock flower | Iridaceae
|
| TIPA6 | Tigridia pavonia (L. f.) DC. | Tigridia grandiflora | Iridaceae
|
| TIPU3 | Tigridia purpurea (Herbert) Shinners | Alophia drummondii | Iridaceae
|
| TIGRI | Tigridia Juss. | peacock flower | Iridaceae
|
| TIAMA | Tilia americana L. var. americana | American basswood | Tiliaceae
|
| TIAMC | Tilia americana L. var. caroliniana (P. Mill.) Castigl. | Carolina basswood | Tiliaceae
|
| TIAMH | Tilia americana L. var. heterophylla (Vent.) Loud. | American basswood | Tiliaceae
|
| TIAMN | Tilia americana L. var. neglecta (Spach) Fosberg | Tilia americana var. americana | Tiliaceae
|
| TIAM | Tilia americana L. | American basswood | Tiliaceae
|
| TIAU2 | Tilia australis Small | Tilia americana var. caroliniana | Tiliaceae
|
| TICAR | Tilia caroliniana P. Mill. var. rhoophila Sarg. | Tilia americana var. caroliniana | Tiliaceae
|
| TICA | Tilia caroliniana P. Mill. | Tilia americana var. caroliniana | Tiliaceae
|
| TICO2 | Tilia cordata P. Mill. | littleleaf linden | Tiliaceae
|
| TIEB | Tilia eburnea Ashe | Tilia americana var. heterophylla | Tiliaceae
|
| TIEU | Tilia europaea L. p.p. | Tilia vulgaris | Tiliaceae
|
| TIFLH | Tilia floridana Small var. hypoleuca Sarg. | Tilia americana var. caroliniana | Tiliaceae
|
| TIFLO | Tilia floridana Small var. oblongifolia Sarg. | Tilia americana var. caroliniana | Tiliaceae
|
| TIFL3 | Tilia floridana Small | Tilia americana var. caroliniana | Tiliaceae
|
| TIGE2 | Tilia georgiana Sarg. | Tilia americana var. caroliniana | Tiliaceae
|
| TIGL | Tilia glabra Vent. | Tilia americana var. americana | Tiliaceae
|
| TIHEM | Tilia heterophylla Vent. var. michauxii (Nutt.) Sarg. | Tilia americana var. heterophylla | Tiliaceae
|
| TIHE | Tilia heterophylla Vent. | Tilia americana var. heterophylla | Tiliaceae
|
| TILA5 | Tilia lasioclada Sarg. | Tilia americana var. heterophylla | Tiliaceae
|
| TILE | Tilia leptophylla (Vent.) Small | Tilia americana var. caroliniana | Tiliaceae
|
| TILEB | Tilia leucocarpa Ashe var. brevipedunculata (Sarg.) Ashe | Tilia americana var. caroliniana | Tiliaceae
|
| TILE2 | Tilia leucocarpa Ashe | Tilia americana var. caroliniana | Tiliaceae
|
| TILI3 | Tilia littoralis Sarg. | Tilia americana var. caroliniana | Tiliaceae
|
| TIMI5 | Tilia michauxii Nutt. | Tilia americana var. heterophylla | Tiliaceae
|
| TIMO2 | Tilia monticola Sarg. | Tilia americana var. heterophylla | Tiliaceae
|
| TINE | Tilia neglecta Spach | Tilia americana var. americana | Tiliaceae
|
| TIPA5 | Tilia palmeri F.C. Gates | Tilia americana var. americana | Tiliaceae
|
| TIPE | Tilia petiolaris DC. | pendent silver linden | Tiliaceae
|
| TIPL | Tilia platyphyllos Scop. | largeleaf linden | Tiliaceae
|
| TIPO4 | Tilia porracea Ashe | Tilia americana var. caroliniana | Tiliaceae
|
| TIPU | Tilia pubescens Ait. | Tilia americana var. caroliniana | Tiliaceae
|
| TITOP | Tilia tomentosa Moench ssp. petiolaris (DC.) So� | Tilia petiolaris | Tiliaceae
|
| TITR2 | Tilia truncata Spach | Tilia americana var. americana | Tiliaceae
|