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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 4411 | Lecidea scutulata | Stirt. | No | Amygdalaria consentiens | 563 | LC NS | ||||
| 4412 | Lecidea segregans | Nyl. | No | Miriquidica pycnocarpa f. pycnocarpa | 766 | LC NS | ||||
| 4413 | Lecidea semipallens | Nyl. | No | Brianaria bauschiana | 873 | LC | ||||
| 4414 | Lecidea siderolithica | Müll. Arg. (1872) | Yes | Lecidea siderolithica | Lecidea nigrogrisea | 753 | DD NR | Lecidea siderolithica | ||
| 4415 | Lecidea silacea | Ach. (1803) | Yes | Lecidea silacea | 772 | LC NS | Lecidea silacea | |||
| 4416 | Lecidea simplex | (Davies) Hook. (1833) | No | Acarospora privigna | 1167 | LC | ||||
| 4417 | Lecidea simplicior | (Ach. ex Nyl.) Lindsay (1867) | No | Gilbertaria contristans | 309 | LC NS | ||||
| 4418 | Lecidea sincerula | Nyl. (1876) | No | Tremolecia atrata | 1438 | LC | ||||
| 4419 | Lecidea socialis | (Körb.) Cromb. | No | Schadonia fecunda | 1310 | VU D2 NR Sc | ||||
| 4420 | Lecidea sorediza | Nyl. | No | Porpidia tuberculosa | 572 | LC | ||||
| 4421 | Lecidea soredizodes | (Lamy ex Nyl.) Lindau (1913) | No | Porpidia soredizodes | 1690 | LC | ||||
| 4422 | Lecidea speirea | (Ach.) Ach. | No | Porpidia speirea | 774 | LC | ||||
| 4423 | Lecidea speirea | auct. brit. p.p. | No | Rhizocarpon umbilicatum | 1279 | LC | ||||
| 4424 | Lecidea sphaeroides | auct. brit. | No | various lecidioid lichens with pale, biatorine apothecia | ||||||
| 4425 | Lecidea spodiza | Nyl. | No | Micarea denigrata | 877 | LC | ||||
| 4426 | Lecidea spododes | Nyl. | No | Micarea nitschkeana | 885 | LC | ||||
| 4427 | Lecidea sporadiza | Stirt. (1874) | No | Trapeliopsis flexuosa | 692 | LC | ||||
| 4428 | Lecidea sporeta | Stirt. (1878) | No | Miriquidica leucophaea | 739 | LC | ||||
| 4429 | Lecidea squalida | Ach. | No | Toninia squalida | 1427 | NT NR Sc | ||||
| 4430 | Lecidea stellulata | Tayl. | No | Buellia stellulata | 216 | LC ?NS | ||||
| 4431 | Lecidea stenospora | (Hepp) Nyl. | No | Bacidia beckhausii | 135 | LC NS | ||||
| 4432 | Lecidea stenotera | auct. brit. p.p. | No | Micarea incrassata | 1631 | LC NS | ||||
| 4433 | Lecidea stenotera | auct. brit. p.p. | No | Protomicarea limosa | 742 | LC NS | ||||
| 4434 | Lecidea stereocaulorum | (Th. Fr.) Nyl. (1866), non Anzi (1862) | No | Catillaria stereocaulorum | 2203 | NT NR | LF | |||
| 4435 | Lecidea stereocaulorum | Anzi | No | Catillaria stereocaulorum | 2203 | NT NR | LF | |||
| 4436 | Lecidea steriza | (Ach.) Vain. | No | Porpidia macrocarpa f. macrocarpa | 568 | LC | ||||
| 4437 | Lecidea stigmatea | Ach. | No | Lecidella stigmatea | 803 | LC | ||||
| 4438 | Lecidea stirtoniana | Zahlbr. | No | 776 | identity uncertain, type not traced, BLS number 0776 no longer used |
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| 4439 | Lecidea strasseri | Zahlbr. (1898) | Yes | Lecidea strasseri | 2877 | NE NR | Lecidea strasseri | |||
| 4440 | Lecidea subcinerascens | auct. brit., non Nyl. | No | Lecidea lactea s. lat. | 737 | LC |