Lecanora

KEY 1: Key to corticolous and lignicolous Lecanora s.l. lacking atranorin and having distinctly pruinose apothecial disks in the western United States

1a. Thallus and/or apothecial margin yellowish green, containing usnic or isousnic acid, epihymenium granular, usually ochre (rarely with blackish green pigment), of POL+ granules, these soluble in K (varia, saligna, symmicta groups) .........................................2

1b. Thallus and apothecial margin color various, not distinctly yellowish green, epihymenium usually granular and variously pigmented, solubility various (dispersa group) ...................................................................................................................................................15

2a. Thallus and/or apothecial margins P+Y or P+O.................................................................................................................................3

2b. Thallus and/or apothecial margins P- .................................................................................................................................................5

3a. Thallus P+O, fumarprotocetraric acid present........................................................... L. austrocalifornica Lendemer & K. Knudsen

3b. Thallus and/or apothecial margins P+Y .............................................................................................................................................4

4a. Apothecia large (~ 0.5–0.8 mm in diameter), amphithecial cortex lacking above, ~100μm below, spores ellipsoid (10–12 × ~5 μm), usually on wood............................................................................................................................................... L. varia (Hoffm.) Ach.

4b. Apothecia small (rarely large than 0.6 mm in diameter), amphithecial cortex distinct above, ~25–65μm below, spores broadly ellipsoid (6.0–9.0 × 6.0–7.5 μm), usually on conifer twigs........................................................... L.densa (Śliva & Wetm.) Printzen

5a. Thallus C+O, containing xanthones, amphithecium ecorticate, distribution maritime......................................................................6

5b. Thallus C-, lacking xanthones, amphithecium usually corticate, distribution various.......................................................................8

6a. Most spores shorter than 10 μm .................................................................................................................. L. substrobilina Printzen

6b. Most spores longer than 10 μm ..........................................................................................................................................................7

7a. Most spores wider than 4 μm, 2 to 3 times longer than wide, maritime California................................................ L. confusa Almb.

7b. Most spores narrower than 4 μm, 3 to 5 times longer than wide, mostly Baja Pennisula, rare in southern California....................... ........................................................................................................................................................................ L. perconfusa Printzen

8a. Amphithecium ecorticate........................................................................... L. perconfusa Printzen (xanthone deficient chemotypes)

8b. Amphithecium corticate .....................................................................................................................................................................9

9a. Most spores narrow (2.8–3.7 μm wide)............................................................................................................................................10

9b. Most spores wide (3.5–6.5 μm wide), apothecial margins not excluded .........................................................................................11

10a. Apothecial margin becoming excluded or excluded from young............................................................................ L. latens Printzen

10b. Apothecial margin prominent when young, becoming level with base ................................................ L. subintricata (Nyl.) Th. Fr.

11a. Most spores shorter than 9.5 μm, mature apothecia large ( 0.5–0.9 mm), becoming conspicuously constricted at the base and disks convex with age.............................................................................................................................. L. laxa (Śliva & Wetm.) Printzen

11b. Most spores longer than 9.5 μm, mature apothecia smaller, not conspicuously constricted at the base and disks plane ................11

12a. Amphithecial cortex distinctly thickened at base (20–40–(60) μm) ................................................................................................13

12b. Amphithecial cortex uniformly thickened (10–20 μm)....................................................................................................................14

13a. Spores narrowly ellipsoid, more than two times longer than wide, most spores longer than 12 μm, epihymenium often with a blackish green pigment........................................................................................................................................... L. mughicola Nyl.

13b. Spores broadly ellipsoid, less than two times longer than wide, most spores shorter than 12 μm, epihymenium granular, lacking blackish green pigment................................................................................................................................. L. coniferarum Printzen

14a. Most spores longer than 12 μm, epihymenium often with a blackish green pigment............................................ L. mughicola Nyl.

14b. Most spores shorter than 12 μm, epihymenium granular, lacking blackish green pigment ...................................... L. albellula Nyl.

15a. Thallus distinct, areolate, usually subsquamulose/lobate.................................................................................................................16

15b. Thallus indistinct, lacking, or of irregularly bullate areoles.............................................................................................................17

16a. Usually on calcareous rocks, rarely on bark or wood, thallus yellowish or cream colored, pruinose, epihymenium yellow or brown, granular, disks orange............................................................................................................................ L. albescens (Hoffm.) Flörke

16b. Only known from bark, thallus light blue, epruinose, epihymenium brownish gray, granular, containing a blue pigment, disks grayish blue ........................................................................................................................ L. indigoana E. Tripp & J. Watts sp. nov.

17a. Thallus of irregularly bullate areoles................................................................................................................................................18

17b. Thallus indistinct or lacking .............................................................................................................................................................19

18a. Epihymenium with a blue pigment, hymenium tall (>60 μm), inspersed with oil droplets................................................................. ........................................................................................................................................... L. indigoana E. Tripp & J. Watts , sp. nov.

18b. Epihymenium lacking blue pigment, hymenium short (<60 μm), not inspised with oil droplets .................................. L. juniperina

19a. Amphithecial cortex expanded basally to 60–100 μm thick, apothecial disk heavily pruinose....................................... L. wetmorei

19b. Amphithecial cortex <60 μm at base, apothecial disk lightly to heavily pruinose.............................................................. L. hagenii