| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| TOMA | Tournefortia maculata Jacq. | bejuco de masa | Boraginaceae
|
| TOMI3 | Tournefortia microphylla Bertol. ex Spreng. | Tournefortia volubilis | Boraginaceae
|
| TOPE2 | Tournefortia peruviana Poir. p.p. | Tournefortia maculata | Boraginaceae
|
| TOPO | Tournefortia poliochros Spreng. | Tournefortia volubilis | Boraginaceae
|
| TOSC3 | Tournefortia scabra Lam. | West Indian soldierbush | Boraginaceae
|
| TOSI | Tournefortia sibirica L. | Argusia sibirica | Boraginaceae
|
| TOVO | Tournefortia volubilis L. | twining soldierbush | Boraginaceae
|
| TOURN | Tournefortia L. | soldierbush | Boraginaceae
|
| TOVIG | Tovara virginiana (L.) Raf. var. glaberrima Fern. | Polygonum virginianum | Polygonaceae
|
| TOVI2 | Tovara virginiana (L.) Raf. | Polygonum virginianum | Polygonaceae
|
| TOTR | Tovaria trifolia (L.) Neck. ex Baker | Maianthemum trifolium | Liliaceae
|
| TOALA | Townsendia alpigena Piper var. alpigena | Wyoming Townsend daisy | Asteraceae
|
| TOALC | Townsendia alpigena Piper var. caelilinensis (Welsh) Kartesz & Gandhi | Wyoming Townsend daisy | Asteraceae
|
| TOALM | Townsendia alpigena Piper var. minima (Eastw.) Dorn | Wyoming Townsend daisy | Asteraceae
|
| TOAL | Townsendia alpigena Piper | Wyoming Townsend daisy | Asteraceae
|
| TOAN | Townsendia annua Beaman | annual Townsend daisy | Asteraceae
|
| TOAN2 | Townsendia anomala Heiser | Townsendia condensata var. anomala | Asteraceae
|
| TOAP | Townsendia aprica Welsh & Reveal | Last Chance Townsend daisy | Asteraceae
|
| TOAR3 | Townsendia arizonica Gray | Townsendia incana | Asteraceae
|
| TOCOA | Townsendia condensata Parry ex Gray var. anomala (Heiser) Dorn | cushion Townsend daisy | Asteraceae
|
| TOCOC | Townsendia condensata Parry ex Gray var. condensata | cushion Townsend daisy | Asteraceae
|
| TOCO2 | Townsendia condensata Parry ex Gray | cushion Townsend daisy | Asteraceae
|
| TOEX | Townsendia eximia Gray | tall Townsend daisy | Asteraceae
|
| TOEX2 | Townsendia exscapa (Richards.) Porter | stemless Townsend daisy | Asteraceae
|
| TOFE | Townsendia fendleri Gray | Fendler's Townsend daisy | Asteraceae
|
| TOFLW | Townsendia florifera (Hook.) Gray var. watsonii (Gray) Cronq. | Townsendia florifera | Asteraceae
|
| TOFL2 | Townsendia florifera (Hook.) Gray | showy Townsend daisy | Asteraceae
|
| TOFO | Townsendia formosa Greene | smooth Townsend daisy | Asteraceae
|
| TOGL4 | Townsendia glabella Gray | Gray's Townsend daisy | Asteraceae
|
| TOGR | Townsendia grandiflora Nutt. | largeflower Townsend daisy | Asteraceae
|
| TOGY | Townsendia gypsophila T.K. Lowrey & P.J. Knight | gymsum-lovingTownsend daisy | Asteraceae
|
| TOHO | Townsendia hookeri Beaman | Hooker's Townsend daisy | Asteraceae
|
| TOIN | Townsendia incana Nutt. | hoary Townsend daisy | Asteraceae
|
| TOIN2 | Townsendia intermedia Rydb. | Townsendia exscapa | Asteraceae
|
| TOJOJ | Townsendia jonesii (Beaman) Reveal var. jonesii | Jones' Townsend daisy | Asteraceae
|
| TOJOL | Townsendia jonesii (Beaman) Reveal var. lutea Welsh | Townsendia aprica | Asteraceae
|
| TOJOT | Townsendia jonesii (Beaman) Reveal var. tumulosa Reveal | Jones' Townsend daisy | Asteraceae
|
| TOJO | Townsendia jonesii (Beaman) Reveal | Jones' Townsend daisy | Asteraceae
|
| TOLE | Townsendia leptotes (Gray) Osterhout | common Townsend daisy | Asteraceae
|
| TOMEJ | Townsendia mensana M.E. Jones var. jonesii Beaman | Townsendia jonesii var. jonesii | Asteraceae
|
| TOME2 | Townsendia mensana M.E. Jones | table Townsend daisy | Asteraceae
|
| TOMI4 | Townsendia microcephala Dorn | smallheaded Townsend daisy | Asteraceae
|
| TOMI2 | Townsendia minima Eastw. | Townsendia alpigena var. minima | Asteraceae
|
| TOMOC | Townsendia montana M.E. Jones var. caelilinensis Welsh | Townsendia alpigena var. caelilinensis | Asteraceae
|
| TOMOM | Townsendia montana M.E. Jones var. minima (Eastw.) Beaman | Townsendia alpigena var. minima | Asteraceae
|
| TOMO | Townsendia montana M.E. Jones | Townsendia alpigena var. alpigena | Asteraceae
|
| TONU | Townsendia nuttallii Dorn | Nuttall's Townsend daisy | Asteraceae
|
| TOPA2 | Townsendia parryi D.C. Eat. | Parry's Townsend daisy | Asteraceae
|
| TOPI | Townsendia pinetorum Greene ex A. Nels. | Townsendia formosa | Asteraceae
|
| TORO | Townsendia rothrockii Gray ex Rothrock | Rothrock's Townsend daisy | Asteraceae
|
| TOSC | Townsendia scapigera D.C. Eat. | tufted Townsend daisy | Asteraceae
|
| TOSEL | Townsendia sericea Hook. var. leptotes Gray | Townsendia leptotes | Asteraceae
|
| TOSE | Townsendia sericea Hook. | Townsendia exscapa | Asteraceae
|
| TOSM | Townsendia smithii L. Shultz & A. Holmgren | Black Rock Townsend daisy | Asteraceae
|
| TOSP | Townsendia spathulata Nutt. | sword Townsend daisy | Asteraceae
|
| TOST | Townsendia strigosa Nutt. | hairy Townsend daisy | Asteraceae
|
| TOTE2 | Townsendia texensis Larsen | Texas Townsend daisy | Asteraceae
|
| TOVR | Townsendia vreelandii Rydb. | Townsendia eximia | Asteraceae
|
| TOWR | Townsendia wrightii (Gray) Gray | Xylorhiza wrightii | Asteraceae
|
| TOWNS | Townsendia Hook. | Townsend daisy | Asteraceae
|
| TODE2 | Toxicodendron desertorum Lunell | Toxicodendron rydbergii | Anacardiaceae
|
| TODI | Toxicodendron diversilobum (Torr. & Gray) Greene | Pacific poison oak | Anacardiaceae
|
| TOPU2 | Toxicodendron pubescens P. Mill. | Atlantic poison oak | Anacardiaceae
|
| TOQU | Toxicodendron quercifolium (Michx.) Greene | Toxicodendron pubescens | Anacardiaceae
|
| TORAD | Toxicodendron radicans (L.) Kuntze ssp. divaricatum (Greene) Gillis | eastern poison ivy | Anacardiaceae
|
| TORAD2 | Toxicodendron radicans (L.) Kuntze ssp. diversilobum (Torr. & Gray) Thorne | Toxicodendron diversilobum | Anacardiaceae
|
| TORAE | Toxicodendron radicans (L.) Kuntze ssp. eximium (Greene) Gillis | eastern poison ivy | Anacardiaceae
|
| TORAN | Toxicodendron radicans (L.) Kuntze ssp. negundo (Greene) Gillis | eastern poison ivy | Anacardiaceae
|
| TORAP | Toxicodendron radicans (L.) Kuntze ssp. pubens (Engelm. ex S. Wats.) Gillis | eastern poison ivy | Anacardiaceae
|
| TORAR | Toxicodendron radicans (L.) Kuntze ssp. radicans | eastern poison ivy | Anacardiaceae
|
| TORAV | Toxicodendron radicans (L.) Kuntze ssp. verrucosum (Scheele) Gillis | eastern poison ivy | Anacardiaceae
|
| TORAD3 | Toxicodendron radicans (L.) Kuntze var. divaricatum (Greene) Barkl. | Toxicodendron radicans ssp. divaricatum | Anacardiaceae
|
| TORAE2 | Toxicodendron radicans (L.) Kuntze var. eximium (Greene) Barkl. | Toxicodendron radicans ssp. eximium | Anacardiaceae
|
| TORAN2 | Toxicodendron radicans (L.) Kuntze var. negundo (Greene) Reveal | Toxicodendron radicans ssp. negundo | Anacardiaceae
|
| TORAP2 | Toxicodendron radicans (L.) Kuntze var. pubens (Engelm. ex S. Wats.) Reveal | Toxicodendron radicans ssp. pubens | Anacardiaceae
|
| TORAR2 | Toxicodendron radicans (L.) Kuntze var. rydbergii (Small ex Rydb.) Erskine | Toxicodendron rydbergii | Anacardiaceae
|
| TORAV2 | Toxicodendron radicans (L.) Kuntze var. verrucosum (Scheele) Barkl. | Toxicodendron radicans ssp. verrucosum | Anacardiaceae
|
| TORA2 | Toxicodendron radicans (L.) Kuntze | eastern poison ivy | Anacardiaceae
|
| TORY | Toxicodendron rydbergii (Small ex Rydb.) Greene | western poison ivy | Anacardiaceae
|
| TOSU | Toxicodendron succedaneum (L.) Kuntze | wax tree | Anacardiaceae
|
| TOTO | Toxicodendron toxicarium Gillis | Toxicodendron pubescens | Anacardiaceae
|
| TOTO2 | Toxicodendron toxicodendron (L.) Britt. | Toxicodendron pubescens | Anacardiaceae
|
| TOVE3 | Toxicodendron vernicifluum (Stokes) F. Barkley | Chinese lacquer | Anacardiaceae
|
| TOVE | Toxicodendron vernix (L.) Kuntze | poison sumac | Anacardiaceae
|
| TOVU | Toxicodendron vulgare P. Mill. | Toxicodendron radicans ssp. radicans | Anacardiaceae
|
| TOXIC | Toxicodendron P. Mill. | poison oak | Anacardiaceae
|
| TOGR3 | Toxicoscordion gramineum (Rydb.) Rydb. | Zigadenus venenosus var. gramineus | Liliaceae
|
| TONU2 | Toxicoscordion nuttallii (Gray) Rydb. | Zigadenus nuttallii | Liliaceae
|
| TOPA5 | Toxicoscordion paniculatum (Nutt.) Rydb. | Zigadenus paniculatus | Liliaceae
|
| TOVE2 | Toxicoscordion venenosum (S. Wats.) Rydb. | Zigadenus venenosus var. venenosus | Liliaceae
|
| TOPO2 | Toxylon pomiferum Raf. ex Sarg. | Maclura pomifera | Moraceae
|
| TRAR6 | Tracaulon arifolium (L.) Raf. | Polygonum arifolium | Polygonaceae
|
| TRSAG | Tracaulon sagittatum (L.) Small var. gracilentum (Fern.) C.F. Reed | Polygonum sagittatum | Polygonaceae
|
| TRSA4 | Tracaulon sagittatum (L.) Small | Polygonum sagittatum | Polygonaceae
|
| TRDI | Trachelospermum difforme (Walt.) Gray | climbing dogbane | Apocynaceae
|
| TRJA | Trachelospermum jasminoides (Lindl.) Lem. | confederate jasmine | Apocynaceae
|
| TRACH | Trachelospermum Lem. | trachelospermum | Apocynaceae
|
| TRME9 | Trachybryum megaptilum (Sull.) Schof. | trachybryum moss | Brachytheciaceae
|
| TRACH4 | Trachybryum (Broth.) Schof. | trachybryum moss | Brachytheciaceae
|
| TRFO3 | Trachycarpus fortunei (Hook.) H. Wendl. | Chinese windmill palm | Arecaceae
|
| TRACH7 | Trachycarpus H. Wendl. | Chinese windmill palm | Arecaceae
|