212 33. LECIDEACEAE [120. Psora 



OTHER SPECIES REPORTED 



Lecidea admiscens Nyl. — Southern California. 

 Lecidea assimilata Nyl. — California. 

 Lecidea glaucopholis Nyl. — California. 

 Lecidea griseoatra (Hoffm.) Flot. — California. 

 Lecidea gyrophoroides Spreng. — Pennsylvania. 

 Lecidea Michenerii (Tuck.) — Pennsylvania. 

 Lecidea microps Tuck. — North Carolina. 

 Lecidea mundula Mull. Arg. — New England. 

 Lecidea recedens Nyl. — North and South Carolina. 

 Lecidea Tuckeii Herre — Nevada. 



120. Psor.3 Hoffm., Descr. PI. Crypt. 1:37. pi. 8, f. 1. 1790. 



Thallus crustose to more or less subfoliose, squamulose, differentiated into a 

 well-developed, more or less gelatinized, cellular upper cortex, an algal layer and 

 an indistinctly medullary layer or sometimes a lower cortex composed of hyphae 

 extending in a horizontal direction, attached to the substratum by more or less 

 numerous hyphal rhizoids; apothecia small to middle-sized or rarely large, adnate 

 or sessile, the disk flat to more or less convex, reddish brown to black, the exciple 

 usually colored like the disk, thin and disappearing; hypothecium hyaline to brown 

 or black; hymenium hyaline to brownish; paraphyses unbranched; asci clavate to 

 cylindrico-clavate; spores 8, hyaline, ellipsoid to oblong, non-septate. 



The algal host is Protococcus. 



A. On old wood or over moss 

 B. On old wood 



C. Apothecia reaching 0.8-1 mm. across 



D. Spores 8-10 X 2.5-3 /x 14. P. ostreata 



D. Spores 7-8.5 X 3-4 n 8. P. Friesii 



C. Apothecia 0.2-0.5 mm. across 7. P. anthracophila 



B. On moss over rocks 4. P. Petri 



A. On rocks and soil 



B. Hypothecium hyaline to yellowish or brownish 

 C. Black hypothallus conspicuous 



D. Squamules brownish gray to ashy white 1. P. demissa 



D. Squamules blackish chestnut-brown 5. P. scotopholis 



C. Hypothallus not conspicuous 



D. Squamules white-edged 6. P. Russellii 



D. Squamules not white-edged 



E. Squamules brownish or greenish to blackish . . . . 3. P. rufonigra 

 E. Squamules dull brownish yellow to dark red .... 2. P. luridelh 

 B. Hypothecium brownish to dark brown 

 C. Squamules white-edged 



D. Squamules smooth or furrowed, flesh-colored to brick-colored 



or whitish 13. P. decipiens 



D. Squamules smooth, pale to darker fawn-colored . . 12. P. rubiformis 



C. Squamules not white-edged, or only rarely so 



D. Squamules greenish gray to ashy or greenish yellow to tawny 



E. Squamules middle-sized, ascending to erect, stipitate . 11. P. caulophylla 

 E. Squamules small, closely adnate to marginally ascending 9. P. icterica 



D. Squamules greenish or reddish to brownish and brown 



E. Squamules middle-sized, greenish to lurid brown ... 15. P.lurida 

 E. Squamules larger, more or less reddish brown 



F. Apothecia 0.5-1.5 mm. across, disk strongly convex . 16. P. globifera 

 F. Apothecia 0.3-0.8 mm. across, disk convex ... 10. P. crenata 



1. Psora demissa (Rutstrom) Stein., in Cohn, Krypt. Flora 2:171. 1879. 



Lichen demissus Rutstrom, Spic. PI. Crypt. Suec. 8. 1794. Lecidea demissa 

 (Rutstrom) Ach. Biatora atrorufa (Dicks.) E. Fries. P.atrorufa (Dicks.) 

 Hook. 



