286 



36. ACAROSPORACEAE [140. Acarospora 



10. Acarospora aeruginosa Hasse, Cont. U.S. Nat. Herb. ll 1 :^!,^. 1913. 

 Thallus of minute, clay-colored, flattened to convex, continuous or scattered 



squamules; apothecia very minute, 0.1-0.15 mm. across, immersed 1-3 in each 

 squamule, the disk punctiform to round or irregular, concave to flat, pale greenish 

 or bluish pruinose ; spores oblong, 3-4 X 1-2 fi. 



On argillaceous clay and granite, southern California. 



11. Acarospora thermophila Herre, Bot. Gaz. 55:394. 1913. 



Thallus of short, black, often branched stipes, and small, surmounting, pale 

 yellowish to clay-brown, orbicular to lobulate squamule-like expansions; apothecia 

 small to middle-sized, 0.3-0.8 mm. across, 1-several in each expansion, the disk flat, 

 more or less rough and sometimes fissured, yellowish brown, the exciple narrow but 

 plainly visible; spores subglobose to short-ellipsoid, 2-4.5 X 1-2 jx. 



Common on rocks, at 4,000 to 8,000 feet, mountains about Reno and Mt. Rose, 

 Nevada. 



12. Acarospora Heppii Naeg., in Koerb., Par. Lich. 61, 62. 1859. 



Thallus very thin, minutely warty, sometimes scarcely visible, greenish gray 

 to brick-red or dusky brown or rarely grayish white; apothecia minute, 0.1-0.2 mm. 

 across, solitary, semi-immersed to adnate, the disk concave to flat, reddish brown 

 to dusky, the exciple prominent, rising above the disk, brownish black; spores 

 ellipsoid, 4-6 X 1.5-2 /x, said to be sometimes globose. 



On rocks, along a stream, Montgomery County, Indiana. Differing considerably 

 from the type and doubtfully included here. 



13. Acarospora immersa Fink; Hedrick, Mycologia 26:158. 1934. 



Thallus thin, smooth to minutely chinky and areolate, dark greenish gray to 

 black; apothecia minute, 0.1-0.15 mm. across, immersed 1 or rarely more in an 

 areole, the disk flat, grayish pruinose, the exciple thin, colored like the thallus, 

 entire; asci clavate and becoming inflated; spores ellipsoid, 3-4 X 1.5—2 /x, irregu- 

 larly arranged. 



On limestone, near Oxford, Ohio. 



14. Acarospora California Zahlbr. ; Hasse, Bryologist 17:62. 1914. 



Thallus of small, continuous or scattered, light tan to pale chocolate colored, 

 sometimes obscurely pruinose areoles or squamules; apothecia minute, 0.15-0.25 

 mm. across, the disk concave and brown, deeply immersed, 1 or rarely 2 or 3 in 

 each areole or squamule; asci narrowly flask-shaped to cylindrico-clavate; spores 

 oblong-ellipsoid, 3-4 X 1.5-2 p. 



On granite, San Jacinto Mountains, California. 



15. Acarospora epilutescens Zahlbr., Beih. Bot. Centralb. 13:161. 1902. 

 Thallus of grayish white to light steel gray or finally light brown, turgid, rough- 

 ened, round to irregular, continuous or scattered squamules; apothecia 1 or rarely 

 more in a squamule, minute or small, 0.2-0.5 mm. across, immersed, the disk flat 

 and black, the thalloid exciple moderately thick, entire or subentire, inflexed; 

 spores subspherical to ovoid, 4-5 X 2.5-4 /a. 



On granite, San Jacinto Mountains, California. 



16. Acarospora cineracea (Nyl.) Wedd., Bull. Soc. Bot. France 21:342. 1874. 

 Lecanora cervina f. cineracea Nyl., Act. Soc. Linn. Bordeaux, 21:440. 1856. 



Lecanora cineracea Nyl. 



Thallus of conspicuous, light brown to white-pruinose, flat or convex, clustered 

 and areolate or scattered and round, irregular, or lobed squamules; apothecia 

 minute," 0.2-0.4 mm. across, immersed, 1-several in each squamule, the disk 

 concave or flat, dark brown; spores oblong-ellipsoid, 4.5-6 X 2-3 p.. 



On shaded basalt, near Tucson, Arizona. 



17. Acarospora arenosa Herre, Proc. Wash. Acad. Sci. 12:128. 1910. 



Thallus thin, composed of small, flat to slightly convex, rough, greenish gray 

 to brownish, scale-like areoles, sometimes crowded into an uneven, chinky crust; 



