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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 4981 | Lichen rufescens | With. | No | Ophioparma ventosa | 556 | LC | ||||
| 4982 | Lichen rugosus | L. | No | Ascodichaena rugosa | Ascodichaena rugosa (L.) Butin | F | ||||
| 4983 | Lichen runcinatus | With. (1776) | No | Anaptychia runcinata | 47 | LC | ||||
| 4984 | Lichen rupestris | Scop. | No | Protoblastenia rupestris | 1189 | LC | ||||
| 4985 | Lichen rupicola | L. (1767) | No | Glaucomaria rupicola var. rupicola | 674 | LC | ||||
| 4986 | Lichen saccatus | L. | No | Solorina saccata | 1330 | LC | ||||
| 4987 | Lichen sanguinarius | L. (1753) | No | Mycoblastus sanguinarius f. sanguinarius | 909 | LC | ||||
| 4988 | Lichen saxatilis | L. | No | Parmelia saxatilis s. str. | 1015 | LC | ||||
| 4989 | Lichen saxicola | Pollich (1771) | No | Protoparmeliopsis muralis | 661 | LC | ||||
| 4990 | Lichen scaber | Huds. | No | ? Pseudephebe pubescens | ||||||
| 4991 | Lichen scabrosus | (Ach.)Sm. (1808) | No | Epilichen scabrosus | 510 | LC NS M* | LF | |||
| 4992 | Lichen scalaris | Ach. ex Lilj. | No | Hypocenomyce scalaris | 578 | LC | ||||
| 4993 | Lichen scopulorum | Retz. | No | Ramalina siliquosa | 1240 | LC | ||||
| 4994 | Lichen scriptus | L. (1753) | No | Graphis scripta s. str. | 2865 | LC | ||||
| 4995 | Lichen scrobiculatus | Scop. (1772) | No | Lobarina scrobiculata | 858 | LC Sc L IR | ||||
| 4996 | Lichen scrobiculatus | With. (1776) | No | Lobarina scrobiculata | 858 | LC Sc L IR | ||||
| 4997 | Lichen scutelliferus | With. | No | Tornabea scutellifera | 1430 | Ex | ||||
| 4998 | Lichen sepincola | sensu Dicks. (1793) | No | Tuckermannopsis chlorophylla | 327 | LC | ||||
| 4999 | Lichen siliquosus | Huds. | No | Ramalina siliquosa | 1240 | LC | ||||
| 5000 | Lichen sinuatus | Huds. (1778) | No | Scytinium gelatinosum | 846 | LC | ||||
| 5001 | Lichen sinuosus | Sm. (1809) | No | Hypotrachyna sinuosa | 1017 | LC Sc IR | ||||
| 5002 | Lichen sparassus | (Ach.) Sm. | No | Cladonia squamosa var. squamosa | 2365 | LC | ||||
| 5003 | Lichen speireus | auct. brit. | No | Rhizocarpon umbilicatum | 1279 | LC | ||||
| 5004 | Lichen sphaeroides | Dicks. (1785) | No | Mycobilimbia sphaeroides | 320 | LC L* | ||||
| 5005 | Lichen spongiosus | Sm. (1804), non Scop. (1772) | No | Solorina spongiosa | 1331 | LC NS | ||||
| 5006 | Lichen spongiosus | With., non Scop. | No | Sticta canariensis | 1365 | VU D2 NR P Sc WaL IR | ||||
| 5007 | Lichen spurius | Ach. | No | Peltigera didactyla | 1053 | LC | ||||
| 5008 | Lichen squamatus | Dicks (1790) non Vill. (1789) | No | Thalloidima squamatum | 2874 | Material seen by Dickson from "Scotia" may not be this species | NE NR | |||
| 5009 | Lichen squamulosus | sensu Sm. (1809), ? non Schrad. (1797) | No | Acarospora fuscata | 10 | LC | ||||
| 5010 | Lichen stellaris | auct. brit. p.m.p. | No | Physcia aipolia | 1113 | LC |