For more information see the Supplementary Notes for the Taxon Dictionary, which explains the names and synonyms, and these Instructions on how to use the online Taxon Dictionary which includes details of the Conservation Evaluation codes.
| Count | Name | Authority | Is Current Name? | Current Taxon Name | Synonyms | BLS Number | Comments | Conservation Evaluation | Group | Account & Map |
|---|---|---|---|---|---|---|---|---|---|---|
| 1801 | Chiodecton myrticola var. sarniense | Salwey ex Mudd (1861) | No | Syncesia myrticola | 352 | NT NS IR | ||||
| 1802 | Chiodecton petraeum | Delise (1856) | No | Syncesia myrticola | 352 | NT NS IR | ||||
| 1803 | Chiodecton petraeum | No | 353 | BLS number no longer used | ||||||
| 1804 | Chiodecton subdiscordans | Nyl. | No | Byssoloma subdiscordans | 221 | NT NR | ||||
| 1805 | Chiographa lyellii | (Sm.) Leight. | No | Phaeographis lyellii | 1102 | NT NS IR | ||||
| 1806 | Chionosphaera coppinsii | P. Roberts (1997) | No | Crittendenia coppinsii | 2031 | NE NR | LF | |||
| 1807 | Chionosphaera lichenicola | Alstrup, B. Sutton & Tønsberg (1993) | No | Crittendenia lichenicola | 2425 | NE NR | LF | |||
| 1808 | Chromatochlamys confusum | Fryday ad int. | No | Swinscowia confusa | 2322 | LC NR E Sc IR | ||||
| 1809 | Chromatochlamys confusum | No | 238 | BLS number no longer used | ||||||
| 1810 | Chromatochlamys geislerioides | Fryday ad. int. | No | Cercidospora decolorella | 2382 | LC NR Sc | ||||
| 1811 | Chromatochlamys geislerioides | No | 314 | BLS number no longer used | ||||||
| 1812 | Chromatochlamys larbalestieri | (A.L. Sm.) H. Mayrhofer & Poelt | No | Thelenella larbalestieri | 899 | VU D2 NR E Sc IR | ||||
| 1813 | Chromatochlamys muscorum var. muscorum | (TH. Fr.) H. Mayrhofer & Poelt (1985) | No | Thelenella muscorum var. muscorum | 901 | LC | ||||
| 1814 | Chromatochlamys muscorum var. octospora | (Nyl.) H. Mayrhofer & Poelt | No | Thelenella muscorum var. octospora | 1778 | NE NR Sc | ||||
| 1815 | Chrysothrix candelaris | (L.) J.R. Laundon (1981) | Yes | Chrysothrix candelaris | Lepraria candelaris | 354 | LC | Chrysothrix candelaris | ||
| 1816 | Chrysothrix chlorina | (Ach.) J.R. Laundon (1981) | Yes | Chrysothrix chlorina | Lepraria chlorina | 355 | LC NS | Chrysothrix chlorina | ||
| 1817 | Chrysothrix chrysophthalma | (P. James) P. James & J.R. Laundon (1981) | Yes | Chrysothrix chrysophthalma | Micarea chrysophthalma | 356 | NT NR Sc IR | Chrysothrix chrysophthalma | ||
| 1818 | Chrysothrix chrysophthalma auct. p.p. | auct. p.p. [with sorediate thallus] | No | Chrysothrix flavovirens | 1925 | name or specific epithet valid but has been misused in the past | LC | |||
| 1819 | Chrysothrix flavovirens | Tønsberg (1994) | Yes | Chrysothrix flavovirens | Chrysothrix chrysophthalma auct. p.p. | 1925 | LC | Chrysothrix flavovirens | ||
| 1820 | Ciliomyces oropensis | (Ces.) Höhn. (1906) | No | Paranectria oropensis subsp. oropensis | 2135 | Paranectria oropensis subsp. oropensis{LF} | LC NS | LF | ||
| 1821 | Circinaria caesiocinerea | (Nyl. ex Malbr.) A. Nordin, Savić & Tibell (2010) | Yes | Circinaria caesiocinerea | Aspicilia caesiocinerea; Aspicilia gibbosa auct. brit.; Lecanora gibbosa auct. brit. | 102 | LC | Circinaria caesiocinerea | ||
| 1822 | Circinaria calcarea | (L.) A. Nordin, Savić & Tibell (2010) | Yes | Circinaria calcarea | Aspicilia calcarea; Lecanora calcarea | 103 | LC | Circinaria calcarea | ||
| 1823 | Circinaria contorta | (Hoffm.) A. Nordin, Savić & Tibell (2010) | Yes | Circinaria contorta | Aspicilia contorta subsp. contorta; Lecanora contorta | 107 | LC | Circinaria contorta | ||
| 1824 | Circinaria contorta subsp. hoffmanniana | (S. Ekman & Fröberg ex R. Sant.) I. Zhdanov (2013) | No | Circinaria hoffmanniana | 113 | LC NS | ||||
| 1825 | Circinaria cupreogrisea | (Th. Fr.) A. Nordin, Savić & Tibell (2010) | No | Aspicilia cupreogrisea | status of British material uncertain | NE | ||||
| 1826 | Circinaria hoffmanniana | (S. Ekman & Fröberg ex R. Sant.) A. Nordin (2016) | Yes | Circinaria hoffmanniana | Aspicilia contorta subsp. hoffmanniana; Lecanora hoffmannii | 113 | LC NS | Circinaria hoffmanniana | ||
| 1827 | Circinaria leprosescens | (Sandst.) A. Nordin, Savić & Tibell (2010) | Yes | Circinaria leprosescens | Aspicilia leprosescens; Lecanora leprosescens | 116 | LC | Circinaria leprosescens | ||
| 1828 | Circinaria tuberculosa | (Ach.) Coppins (2023) | Yes | Circinaria tuberculosa | Aspicilia tuberculosa; Lecanora tuberculosa | 1851 | Ex | Circinaria tuberculosa | ||
| 1829 | Cirrenalia lichenicola | Pérez-Ort. (2020) | Yes | Cirrenalia lichenicola | 2843 | on Mycoblastus caesius | NE NR | LF | Cirrenalia lichenicola | |
| 1830 | Cladina alpestris | (L.) Nyl. | No | Cladonia stellaris | 418 |