| Taeniolella scripta (P. Karst.) S. Hughes = Taeniolina scripta |
| Tephromela aglaea (Sommerf.) Hafellner = Calvitimela aglaea |
| Tephromela armeniaca (DC.) Hertel & Rambold = Calvitimela armeniaca |
| Tetramelas insignis (Nägeli ex Hepp) Kalb = Buellia insignis |
| Tetramelas papillatus (Sommerf.) Kalb = Buellia papillata |
| Tetramelas pulverulentus (Anzi) A. Nordin & Tribell = Buellia pulverulenta |
| Thalloidima candidum (Weber) A. Massal. = Thalloidima coeruleonigricans = Toninia
sedifolia |
| Thalloidima cumulatum (Sommerf.) Hellb. = Stereocaulon cumulatum |
| Thalloidima tumidulum (Sm.) A. Massal. = Toninia tumidula |
| Thelidium acrotellum Arnold = Thelidium minutulum |
| Thelidium aeneovinosum (Anzi) Arnold = Thelidium methorium |
| Thelidium aethioboloides sensu Zschacke = Thelidium minutulum |
| Thelidium auruntii = Thelidium fumidum |
| Thelidium auruntii sensu A.L. Sm. = Thelidium incavatum |
| Thelidium borreri Mudd = Thelidium pyrenophorum |
| Thelidium calcivorum = Thelidium incavatum |
| Thelidium cataractarum (Hepp) = Thelidium fontigenum |
| Thelidium cataractarum = Thelidium microbolum |
| Thelidium cataractarum = Thelidium minutulum |
| Thelidium cataractarum = Thelidium zwackhii |
| Thelidium elaeinum (Borrer) Mudd = Verrucaria elaeina |
| Thelidium epipolytropum Mudd = Cercidospora epipolytropa |
| Thelidium exile Arnold = Thelidium minutulum |
| Thelidium explicatum (Stirt.) Wheldon & A. Wilson = Thelidium pyrenophorum |
| Thelidium hospitum Arnold. = Thelidium minutulum |
| Thelidium immersum Mudd = Thelidium decipiens |
| Thelidium margaceum (Leight.) Zschacke = Thelidium minutulum |
| Thelidium marinum (Deakin) Keissl. = Stigmidium marinum |
| Thelidium mesotropum (Nyl.) A.L. Sm. = Thelidium minutulum |
| Thelidium microbolum (Tuck.) Hasse (1913) = Thelidium fontigenum |
| Thelidium microcarpum (Davies ex Leight.) A.L. Sm. = Thelidium zwackhii |
| Thelidium parvulum = Verrucaria bryoctona |
| Thelidium salweii (Leight. ex Nyl.) Mudd = Acrocordia salweyi |
| Thelidium salweyi (Leight. ex Nyl.) Mudd = Acrocordia salweyi |
| Thelidium sparsulum (Nyl.) A.L. Sm. = Thelidium zwackhii |
| Thelidium subgelatinosum (Sm.) Zschacke = Thelidium zwackhii |
| Thelidium submethorium (Vain.) Zschacke = Thelidium methorium |
| Thelidium subrimulatum = Thelidium pyrenophorum |
| Thelidium terrestre Walt. Watson = Thelidium minutulum |
| Thelidium viride (Deakin) Zahlbr. = Thelidium pyrenophorum |
| Thelocarpon epilithellum Nyl. = Thelocarpon laureri |
| Thelocarpon epithallinum Leight. = Thelocarpon epibolum var. epithallinum |
| Thelocarpon interceptum Nyl. = Thelocarpon laureri |
| Thelocarpon intermixtulum Nyl. = Thelocarpon intermediellum |
| Thelocarpon intermixtulum var. olivaceum (de Lesd.) H. Magn. = Thelocarpon olivaceum |
| Thelotrema agelaea (Ach.) Gray = Phlyctis agelaea |
| Thelotrema hutchinsiae Borrer = Pertusaria hutchinsiae |
| Thelotrema lepadinum f. rupestre (Turner) Cromb. = Thelotrema lepadinum |
| Thelotrema lepadinum var. rupestre Turner = Thelotrema lepadinum |
| Thelotrema lepadinum var. scutelliforme Ach. = Thelotrema lepadinum |
| Thelotrema melaleucum (Sm.) Turner & Borrer = Pertusaria pustulata |
| Thelotrema monosporum, non Nyl. = Thelotrema macrosporum |
| Thelotrema subtile, non Tuck. = Thelotrema petractoides |
| Thermutis compacta (Agardh) A.L. Sm. = non-lichenized Scytonema sp. {cyanobacterium} |
| Thrombium aoristoides I.M. Lamb = Thrombium epigaeum |
| Thrombium cretaceum Walt. Watson = Lecidea lichenicola |
| Thrombium laetevirens (Massee) A.L. Sm. = Verrucaria mucosa |
| Thyrea radiata (Sommerf.) Zahlbr. = Lempholemma radiatum |
| Tichothecium calcaricola (Mudd) Arnold = Endococcus rugulosus |
| Tichothecium cerinarium (Mudd) Berl & Voglino = Lichenodiplis lecanorae |
| Tichothecium erraticum A. Massal. = Muellerella lichenicola |
| Tichothecium gemmiferum = Endococcus propinquus |
| Tichothecium lichenicola (Sommerf. ex Fr.) R. Sant. = Muellerella lichenicola |
| Tichothecium pygmaeum = Muellerella pygmaea |
| Tichothecium pygmaeum var. ecatonosporum (Anzi) G. Winter = Muellerella pygmaea |
| Tichothecium pygmaeum var. erraticum (A. Massal.) Vouaux = Muellerella lichenicola |
| Tichothecium pygmaeum var. ventosicola (Mudd) G. Winter = Muellerella ventosicola |
| Tichothecium rugulosum (Nyl.) Arnold = Endococcus rugulosus |
| Tichothecium squamarioides (Mudd) G. Winter = Polycoccum squamarioides |
| Tichothecium stigma = Endococcus perpusillus |
| Tomasellia ischnobela (Nyl.) Keissl. = Celothelium ischnobelum |
| Tomasellia lactea (Ach.) R.C. Harris = Mycoporum lacteum |
| Toninia caeruleonigricans = Toninia sedifolia |
| Toninia cambrica (Wheldon) Walt. Watson = Stereocaulon leucophaeopsis |
| Toninia candida (Weber) Th. Fr. =, âîçìîæíî Toninia caradocensis (Leight. ex
Nyl.) J. Lahm = Hypocenomyce caradocensis |
| Toninia carbonacea Anzi = Toninia verrucarioides |
| Toninia cervina Lönnr. = Toninia verrucarioides |
| Toninia cumulata (Sommerf.) Th. Fr. = Stereocaulon cumulatum |
| Toninia havaasii H. Magn. = Toninia squalida |
| Toninia kolax Poelt = Toninia verrucarioides |
| Toninia leucophaeoides sensu P. James (1965) (sphalm.) = Stereocaulon leucophaeopsis |
| Toninia leucophaeopsis (Nyl.) Th. Fr. = Stereocaulon leucophaeopsis |
| Toninia leucophaeopsis (Nyl.) Th. Fr. = Stereocaulon leucophaeopsis |
| Toninia lobulata (Sommerf.) Lynge = Bilimbia lobulata |
| Toninia lurida (Arnold) H. Olivier = Toninia physaroides |
| Toninia oribata (Nyl.) P. James = Toninia coelestina |
| Toninia pulvinata (Taylor) H. Olivier = Toninia thiopsora |
| Toninia squamulosa = Bilimbia lobulata |
| Toninia squamulosa Mudd = Toninia aromatica |
| Toninia syncomista Th. Fr. = Bilimbia lobulata |
| Toninia turneri (Leight.) H. Olivier = Toninia aromatica |
| Tornabenia atlantica (Ach.) Kurok. = Tornabea scutellifera |
| Torula cyanescens Kalchbr. = Kalchbrenneriella cyanescens |
| Trachylia stigonella, non (Ach.) Fr. = Cyphelium sessile |
| Trachylia tigillaris (Ach.) Fr. = Cyphelium tigillare |
| Trachylia tympanella (Ach.) Fr. = Cyphelium inquinans |
| Trapelia involuta (Taylor) Hertel = Trapelia glebulosa |
| Trapelia mooreana (Carroll) P. James = Ainoa mooreana |
| Trapelia ornata (Sommerf.) Hertel = Trapelia glebulosa |
| Trapelia vezdaeoides Coppins in sched. = Coppinsia minutissima |
| Tremella corniculata With. = Leptogium corniculatum |
| Tremella dichotomum With. = Collema dichotomum |
| Tremolecia jurana (Schaer.) Hertel = Farnoldia jurana |
| Trichia furfuracea (L.) With. = Chaenotheca furfuracea |
| Trichonectria aculeata Kirschst. = Trichonectria hirta |
| Trichonectria anisospora (Lowen) Van den Boom & Diederich = Pronectria anisospora |
| Trichonectria rubifaciens (Ellis & Everh.) Diederich & Schroers = Nectriopsis
rubifaciens |
| Trichothelium aeneum (Wallr.) R.C. Harris = Porina aenea |
| Trichothelium chloroticum (Ach.) R.C. Harris = Porina chlorotica |
| Trichothelium guentheri (Flot.) R.C. Harris = Porina guentheri |
| Trichothelium lineare (Leight.) R.C. Harris = Porina linearis |
| Trichothyrina cetrariicola (Nyl.) D. Hawksw. = Lichenopeltella cetrariicola |
| Tuckermannopsis chlorophylla (Willd.) Hale = Tuckermanopsis chlorophylla |