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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 4921 | Lichen gracilis | L. (1753) | No | Cladonia gracilis | 392 | LC | ||||
| 4922 | Lichen graniformis | K.G. Hagen (1782) | No | Cliostomum corrugatum | 428 | VU B NR P Eng | ||||
| 4923 | Lichen granulatus | Huds. (1778) (nom. illegit.) | No | Lathagrium auriforme | 433 | LC | ||||
| 4924 | Lichen granulatus | auct. p.p. | No | Scytinium plicatile | 843 | LC | ||||
| 4925 | Lichen griffithii | Sm. | No | Cliostomum griffithii | 429 | LC | ||||
| 4926 | Lichen griseus | Lam. | No | Physconia grisea | 1127 | LC | ||||
| 4927 | Lichen griseus | Sw. ex Westr., non Lam. | No | Umbilicaria grisea | 1448 | |||||
| 4928 | Lichen haematomma | Ehrh., nom. illeg. | No | Haematomma ochroleucum | LC | |||||
| 4929 | Lichen herbaceus | Huds. (1778) | No | Ricasolia virens | 856 | LC Sc L IR | ||||
| 4930 | Lichen heteromallus | Sm. | No | Pilonema heteromallum | Pilonema heteromallum (Sm.) Nyl. | F | ||||
| 4931 | Lichen hirtus | L. | No | Usnea hirta | 1468 | LC | ||||
| 4932 | Lichen hookeri | Borrer ex Sm. | No | Pannaria hookeri | 975 | NT NS Sc | ||||
| 4933 | Lichen humilis | With. | No | Cladonia humilis | 376 | LC | ||||
| 4934 | Lichen hyperellus | Ach. | No | Calicium viride | 231 | LC | ||||
| 4935 | Lichen incanus | sensu Sm. (1807), non (L.) Neck. (1771) | No | Megalospora tuberculosa | 862 | NT NS P Eng Sc Wa IR | ||||
| 4936 | Lichen inclusus | Sm. | No | Thelotrema lepadinum | 1410 | LC L* | ||||
| 4937 | Lichen inquinans | Sm. | No | Calicium inquinans | 474 | LC | ||||
| 4938 | Lichen islandicus | L. | No | Cetraria islandica subsp. islandica | 333 | LC | ||||
| 4939 | Lichen islandicus var. tenuissimus | L. | No | Cetraria aculeata | 430 | LC | ||||
| 4940 | Lichen jacquinii | J.F. Gmel. | No | ? Umbilicaria hyperborea or Umbilicaria proboscidea | ||||||
| 4941 | Lichen jubatus | auct. p.max.p. | No | Bryoria fuscescens | 192 | LC | ||||
| 4942 | Lichen lacerus | With. | No | Ramalina lacera | 1233 | LC | ||||
| 4943 | Lichen laciniatus | Huds. (1762) | No | Ricasolia amplissima | 855 | LC Sc L IR | ||||
| 4944 | Lichen lacteus | L. | No | Varicellaria lactea | 1077 | LC | ||||
| 4945 | Lichen lactucifolius | With. | No | Peltigera sp. | Peltigera sp., identity uncertain | |||||
| 4946 | Lichen lactucæfolius | With. [orth. var.] | No | Peltigera sp. | Peltigera sp., identity uncertain | |||||
| 4947 | Lichen lacustris | With. (1796) | No | Hymenelia lacustris | 573 | LC | ||||
| 4948 | Lichen laetevirens | Lightf. (1777) | No | Ricasolia virens | 856 | LC Sc L IR | ||||
| 4949 | Lichen laevigatus | Sm. | No | Hypotrachyna laevigata | 1002 | LC | ||||
| 4950 | Lichen lanatus | L. | No | Ephebe lanata | 509 | LC |