Lecanoropsis

Ivanovich, Cristóbal, Weber, Lilith, Palice, Zdeněk, Hollinger, Jason, Otte, Volker, Sohrabi, Mohammad, Sheehy, Steve & Printzen, Christian, 2025, A taxonomic revision of the lichen genus Lecanoropsis (Lecanoraceae), Phytotaxa 695 (1), pp. 1-56 : 50-51

Key to Lecanoropsis

1. Epihymenium olive green or blackish................................................................................................................................................ 2

- Epihymenium hyaline or reddish brown, yellow brown, faint brown (pigment deficient L. anopta and L. anoptizodes specimens) or spotted (yellow-brown and olive green) ........................................................................................................................................ 5

2. Thallus episubstratal and well developed; pycnidia conspicuous on thallus, hemispherical, shiny black..... Lecanoropsis coracina

- Thallus endosubstratal or if episubstratal, poorly developed; pycnidia insconspicuous.................................................................... 3

3. Apothecia 0.4–0.7 mm diameter; pycnidia conspicuous or not ........................................................................ Lecanoropsis anopta

- Apothecia 0.25–0.4 mm diameter; pycnidia inconspicuous............................................................................................................... 4

4. Apothecial disc typically flat; margin persistent in old apothecial; guttules absent in hymenium; macroconidia absent ................... ........................................................................................................................................................................... Lecanora mughicola

- Apothecial disc typically strongly convex, becoming subglobose and biatorine-like; margin excluded in old apothecia; guttules typically present in hymenium; macroconidia U-shaped 1–3 septate....................................................... Lecanoropsis anoptizodes

5. Hymenium 30–40 µm (35–45 µm in Lecanoropsis subintricata , but mean height <40 µm) ........................................................... 6

- Hymenium mostly 40–50 µm or more (40–45 µm in Lecanoropsis austrocascadensis , but mean height> 40 µm) ...................... 11

6. Guttules typically present in hymenium; macroconidia present; leptoconidia length 12–15 um; Isousnic acid ................................. ................................................................................................................................................................... Lecanoropsis anoptizodes

- Guttules in the hymenium absent; macroconidia absent; leptoconidia longer or absent; usnic or pseudoplacodiolic acid............... 7

7. Subhymenial layers 10–30 µm high; spore width 2.8–3.3 µm............................................................................ Lecanoropsis latens

- Subhymenial layers 50–145 µm high; spore width 3.0–4.2 µm......................................................................................................... 8

8. Amphithecial cortex pigmented; spore length 8–12 µm .................................................................................................................... 9

- Amphithecial cortex hyaline; spore length 6–10 µm ....................................................................................................................... 10

9. Apothecial discs pale pinkish to orange-brown or reddish brown; epihymenium hyaline or spotted faint orange-brown with faint olive green; amphithecial cortex 24–31(–39) µm laterally, 18–21(–25) µm basally; spores 8.0–10.0(–11.9) × (1.7–)3.1–3.9(–4.3) µm...................................................................................................................................................................... Lecanoropsis omissa

- Apothecial discs pale beige to grey to brown; epihymenium hyaline to faint yellow-brown; amphithecial cortex 32–53(–67) µm laterally, 36–44(–58) µm basally; spores 11.9–12.1(–15.5) × (2.5–)3.0–3.1(–3.5) µm ............................. Lecanoropsis subcinctula

10. Apothecia rounded to irregular, with an uneven, whitish to beige margin with a ragged appearance, whitish to beige; apothecial disc grey, blueish or violaceous, uncommonly beige to brown, typically with coarse pruina; amphithecial cortex narrower, 20–34(–39) µm laterally, (15–)22–27(–32) µm basally; pseudoplacodiolic acid .................................. Lecanoropsis sarcopidoides

- Apothecia rounded, with conspicuous smooth and even, yellow margin; apothecial disc pale yellow or greyish ochre or brown to dark grey; epruinose to occasionally with fine to coarse pruina; amphithecial cortex wider, 25–50(–58) µm laterally, 29–48(–59) µm basally; usnic acid ............................................................................................................................... Lecanoropsis subintricata

11. Amphithecial cortex strongly widened basally 30–100 µm on average .......................................................................................... 12

- Amphithecial cortex not or moderately widened basally, ecorticated to 55 µm on average............................................................ 13

12. Epihymenial pigment faint brown; Hymenium 43–62 µm; spores 8.4–12.0 x 4.6–5.8 µm......................... Lecanoropsis subravida

- Epihymenial pigment reddish brown; Hymenium 68–73 µm; spores 11–14 x 6–6.6 µm ....................... Lecanoropsis coniferarum

13. Spores 6–8 × 2.5–3.5 µm; so far only known from southern Scotland.......................................................... Lecanoropsis coppinsii

- Spores either longer, wider or both; widespread in the Northern Hemisphere ................................................................................ 14

14. Spore mean width 3.5–4 µm, L:W ratio 2.6–3.0.............................................................................................................................. 15

- Spore mean width> 4 µm. L:W ratio <2.6 ..................................................................................................................................... 17

15. Thallus well developed; amphithecium ecorticated ............................................................................... Lecanoropsis crassithallina

- Thallus endosubstratal or poorly developed, rarely well developed; amphithecium corticated ...................................................... 16

16. Apothecia 0.4–0.55 mm; subhymenial layers 60–85 µm; amphithecial cortex 36–38(–56) µm basally, heavily gelatinized at the base, sometimes pigmented faint brown; pseudoplacodiolic acid................................................... Lecanoropsis austrocascadensis

- Apothecia 0.5–0.7 mm; subhymenial layers 95–135 µm; amphithecial cortex 13–20(–28) µm basally, moderately gelatinized at the base, hyaline; isousnic acid .................................................................................................................................. Lecanoropsis iapyx

17. Apothecial discs typically glossy; spores on average 11–12 × 5–6 µm ............................................................ Lecanoropsis micans

- Apothecial discs typically matte, rarely weakly glossy; spores on average either shorter, narrower or both.................................. 18

18. Apothecial margin persistent............................................................................................................................................................ 19

- Apothecial margin often excluded in old apothecia ......................................................................................................................... 22

19. Epihymenium pigment N+ reddish-violet; leptoconidia frequent, 22–27 µm long ...................................... Lecanoropsis calabrica

- Epihymenium pigment N- or orange intensifying; leptoconidia shorter if present.......................................................................... 20

20. Apothecia 0.2–0.5 mm; amphithecium cortex poorly developed; macroconidia 8.5–9.5 × 2.5–3.2 µm .... Lecanoropsis quercicola

- Apothecia 0.4–0.8 mm; amphithecium cortex distinct; macroconidia 7–8 × 2–2.5 µm if present .................................................. 21

21. Apothecial discs typically beige, sometimes almost black; amphithecial cortex variable, 18–54 µm basally; leptoconidia 15–20 µm long.................................................................................................................................................................... Lecanora prolificans

- Apothecial discs typically reddish brown, sometimes pale ochre to dark brown; amphithecial cortex 19–30 µm basally; leptoconidia 8–11 µm long..................................................................................................................................................... Lecanoropsis saligna

22. Apothecia 0.4–0.9 mm; subhymenial layers 60–90 µm; macroconidia not known; leptoconidia 10–17 × 0.7–0.9 µm ................. 23

- Apothecia 0.2–0.5(–0.55) mm; guttules absent in the hymenium; macroconidia common; microconidia longer, up to 10 μm long; leptoconidia 12–25 × 1–2 μm........................................................................................................................................................... 24

23. Apothecia 0.45–0.7 mm; apothecial discs darker, typically dark brown to black; apothecial margin when present whitish-grey; subhymenial layers 80–140; microconidia aseptate .......................................................................................... Lecanoropsis anopta

- Apothecia 0.4–0.9 mm; apothecial discs paler, typically pinkish or orange to red or grey to dark brown; apothecial margin when present yellowish grew or brown, paler to concolorous to darker than the disc; subhymenial layers 60–90; microconidia 1-septate ..................................................................................................................................................... Lecanoropsis pseudosarcopidoides

24. Subhymenial layers 60–130 μm; macroconidia reniform with obtuse tips, 0–3 septate, 7–12 × 1.5–2 µm (12–15 × 1.5–2.5 in L. albellula var. macroconidiata ) ....................................................................................................................... Lecanoropsis albellula

- Subhymenial layers 35–55 μm; macroconidia U-shaped with acute tips, 1–3 septate, 20–25 × 2 μm....... Lecanoropsis subsaligna