The page lists lichen species that are threatened or near threatened, ie Critically Endangered (CR), Endangered (EN), Vulnerable (VU) or Near Threatened (NT).
| Count | Name | Conservation Evaluation |
|---|---|---|
| 1 | Teloschistes chrysophthalmos | CR B, C2, D NR P |
| 2 | Teloschistes flavicans | VU A NS P Eng Wa S8 |
| 3 | Tetramelas insignis | CR D NR Sc |
| 4 | Tetramelas papillatus | CR D NR Sc |
| 5 | Thalloidima physaroides | CR B2, C2 NR P Eng |
| 6 | Thalloidima rosulatum | EN D NR Sc |
| 7 | Thalloidima sedifolium | LC P Eng Wa |
| 8 | Thelenella larbalestieri | VU D2 NR E Sc IR |
| 9 | Thelenella modesta | CR B NR P Sc |
| 10 | Thelidium fumidum | NT NR |
| 11 | Thelocarpon opertum | NT NR E Sc IR |
| 12 | Thermutis velutina | NT NR Sc |
| 13 | Toensbergia geminipara | NT NR Sc |
| 14 | Toninia plumbina | NT NR Sc |
| 15 | Toninia squalida | NT NR Sc |
| 16 | Toniniopsis coelestina | VU D1, D2 NR Sc |
| 17 | Toniniopsis separabilis | VU C, D1 NS P Eng Sc |
| 18 | Topeliopsis azorica | EN D NR Sc |
| 19 | Trimmatothelopsis rhizobola | VU D2 NR Sc |
| 20 | Tylophoron hibernicum | NT NR P Eng Wa IR |