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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 331 | Arthonia gelidae | R. Sant. (1986) | Yes | Arthonia gelidae | 1961 | NE NR | LF | Arthonia gelidae | ||
| 332 | Arthonia glaucomaria | Nyl. (1856) | No | Arthonia varians | 714 | LC NS | LF | |||
| 333 | Arthonia granitophila | Th. Fr. (1865) | Yes | Arthonia granitophila | Melaspilea granitophila; Melaspilea subarenacea | 868 | LC NS | Arthonia granitophila | ||
| 334 | Arthonia graphidicola | Coppins (1989) | Yes | Arthonia graphidicola | 735 | LC NS Sc IR | LF | Arthonia graphidicola | ||
| 335 | Arthonia gregaria | (Weigel) Körb., non Fée | No | Coniocarpon cinnabarinum | 72 | LC | ||||
| 336 | Arthonia gregaria f. cuspidans | (Nyl.) A.L. Sm. (1926) | No | Coniocarpon cuspidans | 58 | LC | ||||
| 337 | Arthonia gregaria var. dubia | (Turner & Borrer) Mudd | No | Coniocarpon cinnabarinum | 72 | LC | ||||
| 338 | Arthonia gregaria var. kermesina | (Schaer.) Willey (1890) | No | Coniocarpon cinnabarinum | 72 | LC | ||||
| 339 | Arthonia gregaria var. kermesina | (Schaer.) Willey (1890) | No | Coniocarpon cinnabarinum | 72 | LC | ||||
| 340 | Arthonia hibernica | Nyl. (1876) | No | Arthonia excipienda | 1599 | NT NR Sc | F | |||
| 341 | Arthonia hypnophila | Coppins ad int. | No | Arthonia mediella | 413 | LC NS | ||||
| 342 | Arthonia ilicina | Taylor (1836) | Yes | Arthonia ilicina | Arthothelium ilicinum | 94 | LC Sc IR | Arthonia ilicina | ||
| 343 | Arthonia ilicinella | Nyl. (1867) | Yes | Arthonia ilicinella | 62 | NT NS E Sc IR | Arthonia ilicinella | |||
| 344 | Arthonia impolita | (Hoffm.) Borrer | No | Pachnolepia pruinata | 63 | LC | ||||
| 345 | Arthonia insinuata | Stirt. (1876) | No | Naevia punctiformis | 68 | LC | F | |||
| 346 | Arthonia intexta | Almq. (1880) | Yes | Arthonia intexta | 1933 | NE NR | LF | Arthonia intexta | ||
| 347 | Arthonia invadens | Coppins (1989) | Yes | Arthonia invadens | 729 | NT NR E P Eng Sc IR | LF | Arthonia invadens | ||
| 348 | Arthonia lapidicola | (Taylor) Branth & Rostr. (1869), non sensu auct. | No | Bryostigma lapidicola | 64 | name usually applied to what is now Arthonia fusca | LC NS | |||
| 349 | Arthonia lapidicola | auct. | No | Arthonia fusca | 64 | LC | ||||
| 350 | Arthonia lecanoricola | Alstrup & Olech (1996) | Yes | Arthonia lecanoricola | 2630 | lichenicolous in apothecia of Lecanora populicola | NE NR | LF | Arthonia lecanoricola | |
| 351 | Arthonia lepidophila | auct. brit. | Yes | Arthonia lepidophila | 2747 | Parasitic on Cladonia. Name is not validly published. | NE NR | LF | Arthonia lepidophila | |
| 352 | Arthonia leucodontis | (Poelt & Döbbeler) Coppins (1989) | No | Bryostigma lapidicola | 1700 | LC NS | ||||
| 353 | Arthonia leucopellaea | (Ach.) Almq. (1880) | No | Felipes leucopellaeus | 65 | LC NS | ||||
| 354 | Arthonia ligniaria | Hellb. (1884) | Yes | Arthonia ligniaria | 1536 | LC NS | Arthonia ligniaria | |||
| 355 | Arthonia ligniariella | Coppins (1989) | Yes | Arthonia ligniariella | 1742 | LC NS | Arthonia ligniariella | |||
| 356 | Arthonia lilliei | B. de Lesd. (1910) | No | Catillaria lenticularis | 311 | LC | ||||
| 357 | Arthonia lirellans | Almq. (1880) | No | Arthothelium lirellans | 1569 | LC NS Sc IR | F | |||
| 358 | Arthonia lobata | (Flörke) A. Massal., et auct brit. p.min.p. | No | Sparria endlicheri | 59 | LC ?NS Sc | ||||
| 359 | Arthonia lobata | auct. brit. p.max.p. | No | Dirina massiliensis f. sorediata | 500 | LC | ||||
| 360 | Arthonia lurida | auct. brit. p.max.p. pre-1980 | No | Arthonia didyma | 56 | LC |