List of species and infraspecific taxa
- Species: Thelidium pyrenophorum (Ach.) Mudd
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Thelidium zwackhii (Hepp) A. Massal.
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Thelocarpon epibolum Nyl.
- Remark:
- Fungus type: lichenicolous
- Treatment in Estonia: certain
- Species: Thelocarpon impressellum Nyl.
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Thelocarpon laureri (Flot.) Nyl.
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Thelocarpon lichenicola (Fuckel) Poelt & Hafellner
- Remark:
- Fungus type: lichenicolous
- Treatment in Estonia: certain
- Species: Thelomma ocellatum (Körb.) Tibell
- Remark: see: Pseudothelomma ocellatum
- Fungus type: lichenized
- Treatment in Estonia: synonym
- Species: Thelopsis flaveola Arnold
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Thelotrema lepadinum (Ach.) Ach.
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- harilik koobassamblik
- Species: Thelotrema suecicum (H. Magn.) P. James
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Thrombium epigaeum (Pers.) Wallr.
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: doubtful
- Species: Toninia physaroides (Opiz) Zahlbr.
- Remark: see: Thalloidima physaroides
- Fungus type: lichenized
- Treatment in Estonia: synonym
- sammas-nappsamblik
- Species: Toninia sedifolia (Scop.) Timdal
- Remark: see: Thalloidima sedifolium
- Fungus type: lichenized
- Treatment in Estonia: synonym
- sinakas nappsamblik
- Species: Toninia verrucarioides (Nyl.) Timdal
- Remark: see: Toniniopsis verrucarioides
- Fungus type: lichenized
- Treatment in Estonia: synonym
- pruunikas nappsamblik
- Species: Trapelia coarctata (Sm.) M. Choisy
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Trapelia glebulosa (Sm.) J.R. Laundon
- Remark: earlier under Trapelia involuta (Taylor) Hertel
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Trapelia involuta (Taylor) Hertel
- Remark: see: Trapelia glebulosa
- Fungus type: lichenized
- Treatment in Estonia: synonym
- Species: Trapelia placodioides Coppins & P. James
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Trapeliopsis flexuosa (Fr.) Coppins & P. James
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Trapeliopsis glaucolepidea (Nyl.) Gotth. Schneid.
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Trapeliopsis granulosa (Hoffm.) Lumbsch
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- tera-varisesamblik
- Species: Trapeliopsis pseudogranulosa Coppins & P. James
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Trapeliopsis viridescens (Schrad.) Coppins & P. James
- Remark:
- Fungus type: lichenized
- Treatment in Estonia: certain
- Species: Tremella cetrariicola Diederich & Coppins
- Remark:
- Fungus type: lichenicolous
- Treatment in Estonia: certain
- Species: Tremella cladoniae Diederich & M.S. Christ.
- Remark:
- Fungus type: lichenicolous
- Treatment in Estonia: certain