| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| THOCC | Thalictrum occidentale Gray var. columbianum (Rydb.) M.E. Peck | Thalictrum venulosum | Ranunculaceae
|
| THOCM2 | Thalictrum occidentale Gray var. megacarpum (Torr.) St. John | Thalictrum occidentale | Ranunculaceae
|
| THOCP2 | Thalictrum occidentale Gray var. palousense St. John | Thalictrum occidentale | Ranunculaceae
|
| THOC | Thalictrum occidentale Gray | western meadow-rue | Ranunculaceae
|
| THPE5 | Thalictrum perelegans Greene | Thalictrum pubescens | Ranunculaceae
|
| THPO | Thalictrum polycarpum (Torr.) S. Wats. | Thalictrum fendleri var. polycarpum | Ranunculaceae
|
| THPOH | Thalictrum polygamum Muhl. ex Spreng. var. hebecarpum Fern. | Thalictrum pubescens | Ranunculaceae
|
| THPOI | Thalictrum polygamum Muhl. ex Spreng. var. intermedium Boivin | Thalictrum pubescens | Ranunculaceae
|
| THPO8 | Thalictrum polygamum Muhl. ex Spreng. | Thalictrum pubescens | Ranunculaceae
|
| THPUH | Thalictrum pubescens Pursh var. hebecarpum (Fern.) Boivin | Thalictrum pubescens | Ranunculaceae
|
| THPUH2 | Thalictrum pubescens Pursh var. hepaticum (Greene) Keener | Thalictrum pubescens | Ranunculaceae
|
| THPU2 | Thalictrum pubescens Pursh | king of the meadow | Ranunculaceae
|
| THREG | Thalictrum revolutum DC. var. glandulosior Boivin | Thalictrum revolutum | Ranunculaceae
|
| THRE | Thalictrum revolutum DC. | waxyleaf meadow-rue | Ranunculaceae
|
| THSPR2 | Thalictrum sparsiflorum Turcz. ex Fisch. & C.A. Mey. ssp. richardsonii (Gray) Cody | Thalictrum sparsiflorum var. richardsonii | Ranunculaceae
|
| THSPN | Thalictrum sparsiflorum Turcz. ex Fisch. & C.A. Mey. var. nevadense Boivin | Thalictrum sparsiflorum var. saximontanum | Ranunculaceae
|
| THSPR | Thalictrum sparsiflorum Turcz. ex Fisch. & C.A. Mey. var. richardsonii (Gray) Boivin | Richarson's meadow-rue | Ranunculaceae
|
| THSPS | Thalictrum sparsiflorum Turcz. ex Fisch. & C.A. Mey. var. saximontanum Boivin | fewflower meadow-rue | Ranunculaceae
|
| THSP | Thalictrum sparsiflorum Turcz. ex Fisch. & C.A. Mey. | fewflower meadow-rue | Ranunculaceae
|
| THST3 | Thalictrum steeleanum Boivin | Thalictrum coriaceum | Ranunculaceae
|
| THSU2 | Thalictrum subrotundum Boivin | Thalictrum macrostylum | Ranunculaceae
|
| THTE | Thalictrum texanum (Gray) Small | Houston meadow-rue | Ranunculaceae
|
| THTH2 | Thalictrum thalictroides (L.) Eames & Boivin | rue anemone | Ranunculaceae
|
| THTU | Thalictrum turneri Boivin | Thalictrum venulosum | Ranunculaceae
|
| THVEC | Thalictrum venulosum Trel. var. confine (Fern.) Boivin | Thalictrum venulosum | Ranunculaceae
|
| THVEF | Thalictrum venulosum Trel. var. fissum (Greene) Boivin | Thalictrum venulosum | Ranunculaceae
|
| THVEL | Thalictrum venulosum Trel. var. lunellii (Greene) Boivin | Thalictrum venulosum | Ranunculaceae
|
| THVET | Thalictrum venulosum Trel. var. turneri (Boivin) Boivin | Thalictrum venulosum | Ranunculaceae
|
| THVE | Thalictrum venulosum Trel. | veiny meadow-rue | Ranunculaceae
|
| THALI2 | Thalictrum L. | meadow-rue | Ranunculaceae
|
| THAL9 | Thamnium alleghaniense (C. M�ll.) Jaeg. | Thamnobryum alleghaniense | Thamnobryaceae
|
| THBI3 | Thamnium bigelovii (Sull.) Jaeg. | Porotrichum bigelovii | Thamnobryaceae
|
| THAL7 | Thamnobryum alleghaniense (C. M�ll.) Nieuwl. | Allegany thamnobryum moss | Thamnobryaceae
|
| THLE7 | Thamnobryum leibergii (Britt.) Ren. & Card. | Thamnobryum neckeroides | Thamnobryaceae
|
| THNE4 | Thamnobryum neckeroides (Hook.) Lawt. | Necker's thamnobryum moss | Thamnobryaceae
|
| THAMN2 | Thamnobryum Nieuwl. | thamnobryum moss | Thamnobryaceae
|
| THCR3 | Thamnogala crombiei (Mudd) D. Hawksw. | | Phyllachoraceae
|
| THAMN4 | Thamnogala D. Hawksw. | thamnogala | Phyllachoraceae
|
| THSU60 | Thamnolia subuliformis (Ehrh.) Culb. | whiteworm lichen | Uncertain Lichen Family
|
| THSU7 | Thamnolia subvermicularis Asah. | Thamnolia subuliformis | Uncertain Lichen Family
|
| THVE60 | Thamnolia vermicularis (Sw.) Ach. ex Schaerer | whiteworm lichen | Uncertain Lichen Family
|
| THAMN3 | Thamnolia Ach. ex Schaerer | whiteworm lichen | Uncertain Lichen Family
|
| THMO | Thamnosma montana Torr. & Fr�m. | turpentinebroom | Rutaceae
|
| THTE2 | Thamnosma texana (Gray) Torr. | rue of the mountains | Rutaceae
|
| THAMN | Thamnosma Torr. & Fr�m. | desertrue | Rutaceae
|
| THAUT | Thaspium aureum (L.) Nutt. var. trifoliatum (L.) Coult. & Rose | Thaspium trifoliatum var. trifoliatum | Apiaceae
|
| THAU5 | Thaspium aureum (L.) Nutt. | Thaspium trifoliatum var. aureum | Apiaceae
|
| THBAA | Thaspium barbinode (Michx.) Nutt. var. angustifolium Coult. & Rose | Thaspium barbinode | Apiaceae
|
| THBA | Thaspium barbinode (Michx.) Nutt. | hairyjoint meadowparsnip | Apiaceae
|
| THCH2 | Thaspium chapmanii (Coult. & Rose) Small | Thaspium barbinode | Apiaceae
|
| THMO7 | Thaspium montanum Gray | Pseudocymopterus montanus | Apiaceae
|
| THPI | Thaspium pinnatifidum (Buckl.) Gray | cutleaf meadowparsnip | Apiaceae
|
| THTRA | Thaspium trifoliatum (L.) Gray var. aureum Britt. | purple meadowparsnip | Apiaceae
|
| THTRF | Thaspium trifoliatum (L.) Gray var. flavum Blake | Thaspium trifoliatum var. aureum | Apiaceae
|
| THTRT | Thaspium trifoliatum (L.) Gray var. trifoliatum | purple meadowparsnip | Apiaceae
|
| THTR | Thaspium trifoliatum (L.) Gray | purple meadowparsnip | Apiaceae
|
| THASP | Thaspium Nutt. | meadowparsnip | Apiaceae
|
| THDA2 | Thaumatococcus daniellii (Bennett) Benth. | miracle fruit | Marantaceae
|
| THAUM | Thaumatococcus Benth. | thaumatococcus | Marantaceae
|
| THBO2 | Thea bohea L. | Camellia sinensis var. sinensis | Theaceae
|
| THSI5 | Thea sinensis L. | Camellia sinensis var. sinensis | Theaceae
|
| THVI3 | Thea viridis L. | Camellia sinensis var. sinensis | Theaceae
|
| THSI3 | Thecophyllum sintenisii (Baker) Mez | Vriesea sintenisii | Bromeliaceae
|
| THGR8 | Thelechitonia gracilis (L.C. Rich.) H.E. Robins. & Cuatrec. | Sphagneticola gracilis | Asteraceae
|
| THTR10 | Thelechitonia trilobata (L.) H.E. Robins. & Cuatrec. | Sphagneticola trilobata | Asteraceae
|
| THBR3 | Thelenella brasiliensis (Mull. Arg.) Vainio | | Thelenellaceae
|
| THCI3 | Thelenella cinerascens (Mull. Arg.) R. C. Harris | | Thelenellaceae
|
| THFU | Thelenella fugiens (mull. Arg.) R. C. Harris | | Thelenellaceae
|
| THGE3 | Thelenella geminipara (Malme) R. C. Harris | | Thelenellaceae
|
| THHA3 | Thelenella harrisii H. Mayrh. | | Thelenellaceae
|
| THHA4 | Thelenella hassei (Zahlbr.) H. Mayrh. | | Thelenellaceae
|
| THHU4 | Thelenella humilis R. C. Harris | | Thelenellaceae
|
| THIN7 | Thelenella inductula (Nyl.) H. Mayrh. | | Thelenellaceae
|
| THLU2 | Thelenella luridella R. C. Harris | | Thelenellaceae
|
| THMO8 | Thelenella modesta (Nyl.) Nyl. | | Thelenellaceae
|
| THPE7 | Thelenella pertusariella (Nyl.) Vainio | | Thelenellaceae
|
| THRA4 | Thelenella rappii R. C. Harris | | Thelenellaceae
|
| THSA10 | Thelenella sastreana R. C. Harris | | Thelenellaceae
|
| THSO | Thelenella sordidula (Th. Fr.) H. Mayrh. | | Thelenellaceae
|
| THSY | Thelenella synchnogonioides (Zahlbr.) R. C. Harris | | Thelenellaceae
|
| THWE | Thelenella weberi H. Mayrh. | | Thelenellaceae
|
| THELE2 | Thelenella Nyl. | thelenella | Thelenellaceae
|
| THAM4 | Thelesperma ambiguum Gray | Colorado greenthread | Asteraceae
|
| THBU | Thelesperma burridgeanum (Regel, Korn. & Rach.) Blake | Burridge's greenthread | Asteraceae
|
| THCA11 | Thelesperma caespitosum Dorn | low greenthread | Asteraceae
|
| THCU2 | Thelesperma curvicarpum T.E. Melchert | Edwards Plateau greenthread | Asteraceae
|
| THFIF | Thelesperma filifolium (Hook.) Gray var. filifolium | stiff greenthread | Asteraceae
|
| THFII | Thelesperma filifolium (Hook.) Gray var. intermedium (Rydb.) Shinners | stiff greenthread | Asteraceae
|
| THFI | Thelesperma filifolium (Hook.) Gray | stiff greenthread | Asteraceae
|
| THFL | Thelesperma flavodiscum (Shinners) B.L. Turner | East Texas greenthread | Asteraceae
|
| THFR | Thelesperma fraternum Shinners | Thelesperma ambiguum | Asteraceae
|
| THGR4 | Thelesperma gracile (Torr.) Gray | Thelesperma megapotamicum | Asteraceae
|
| THIN5 | Thelesperma intermedium Rydb. | Thelesperma filifolium var. intermedium | Asteraceae
|
| THLO | Thelesperma longipes Gray | longstalk greenthread | Asteraceae
|
| THMA5 | Thelesperma marginatum Rydb. | Thelesperma subnudum var. marginatum | Asteraceae
|
| THMEA | Thelesperma megapotamicum (Spreng.) Kuntze var. ambiguum (Gray) Shinners | Thelesperma ambiguum | Asteraceae
|
| THME | Thelesperma megapotamicum (Spreng.) Kuntze | Hopi tea greenthread | Asteraceae
|
| THNU | Thelesperma nuecense B.L. Turner | Rio Grande greenthread | Asteraceae
|
| THPU4 | Thelesperma pubescens Dorn | hairy greenthread | Asteraceae
|
| THSI | Thelesperma simplicifolium Gray | slender greenthread | Asteraceae
|
| THSUA | Thelesperma subnudum Gray var. alpinum Welsh | Thelesperma pubescens | Asteraceae
|