140. Acarospora J 36. ACAROSPORACEAE 287 



apothecia small to middle-sized, 0.3-0.7 mm. across, 1 or rarely more partly im- 

 mersed in an areole, the disk flat to slightly convex, black, the proper exciple thin, 

 black, becoming irregular, surrounded by a very thin, soon disappearing, thalloid 

 one; hypothecium hyaline to brownish; spores numerous, hyaline, ellipsoid, non- 

 septate, 2.5-4 X 1-1.5 fi. 



On sandstone, southern California. 



18. Acarospora Hassei Herre, Proc. Wash. Acad. Sci. 12:128. 1910. 



Thallus of irregular, thick, sometimes lobate, often scattered areoles or squam- 

 ules, pale greenish gray to dusky yellowish or brown, beneath pale yellowish to 

 brown; apothecia small, 0.4-0.6 mm. across, immersed 1-several in each areole, 

 the disk slightly concave to flat, reddish brown; hypothecium hyaline to yellow- 

 ish; spores 3-5 X 1-1.5 /x. 



On sandstone, at 3,000 feet, Santa Cruz Peninsula, California. 



19. Acarospora cervina (Ach.) Mass., Ric. Lich. 28. f. 46. 1852. 



Lecanora cervina Ach., Syn. Lich. 188, 189. 1814. Parmelia cervina (Ach.) Hepp. 

 A. cervina var. cinereoalba Fink. A. cervina var. pruinosa Mass. A.smarag- 

 dula (Wahl.) Mass. 



Thallus of small, yellowish brown to dark chestnut, subpellate or crenate-lobate, 

 closely adnate, scattered or contiguous-areolate and often imbricated squamules, 

 sometimes becoming ashy white; apothecia small to middle-sized, 0.3-0.8 mm. 

 across, 1-3 or 4 in each areole, immersed or becoming superficial, the disk flat 

 and reddish brown or very rarely pruinose, the entire thalloid exciple disappear- 

 ing; spores subspherical to oblong, 3-5 X 1.5-3 \x. 



On rocks other than calcareous, throughout northern United States. 



20. Acarospora obpallens (Nyl.) Zahlbr., Beih. Bot. Centralb. 13:161, 162. 1902. 

 Lecanora obpallens Nyl.; Hasse, Bull. Torr. Club 24:446. 1897. 



Thallus of shining, light chestnut, crowded or scattered, somewhat wrinkled and 

 pitted, convex and rounded squamules; apothecia small to middle-sized, 0.4-0.6 mm. 

 across, partly immersed, 1-several in each squamule, the disk concave to flat, 

 papillate, reddish brown and sometimes obscurely pruinose, the thalloid exciple 

 prominent, moderately thick, crenulate; spores oblong-ellipsoid, 3-6 X 1.5-2 /a. 



On soil and crumbling sandstone, southern California. 



21. Acarospora Carnegiei Zahlbr., Bull. Torr. Club 35:297. 1908. 



Thallus of small, angular or reddish brown and darkening, round, clustered or 

 more or less scattered squamules; apothecia immersed, middle-sized, 0.4-0.7 mm. 

 across, 1-3 in each squamule, the disk flat to slightly convex, pruinose; spores 

 oblong, 5-6 X 1.5-2.5 fj.. 



On blocks of basalt, near Tucson, Arizona. 



22. Acarospora squamulosa (Schrad.) Trevis., Riv. Per. Ace. Padova 263. 



1851-52. 

 Lichen squamulosus Schrad., Ann. Bot. Usteri, 22:84. 1797. Parmelia cervina 

 var. squamulosa (Schrad.) E. Fries. Lecanora cervina var. squamulosa 

 (Schrad.) Willey. 

 Thallus brown to grayish brown, squamulose, the squamules round, entire to 

 lobulate, flat to convex, crowded to scattered; apothecia small to middle-sized, 

 0.25-1 mm. across, immersed to semi-immersed, 1-12 or more in each squamule, 

 the disk flat, chestnut-brown to dull black; spores oblong-ellipsoid, 3-5 X 1.8-2.5 /x. 

 On various rocks, Santa Monica Range, California. 



23. Acarospora fuscata (Schrad.) Arm, Verh. Ges. Wien. 22:279. 1872. 

 Lichen juscatus Schrad., Spic. Fl. Germ. 83. 1794. A. cervina var. jnscata Fink. 



Lecanora fuscata (Schrad.) Rohl. Lecanora fuscata var. rufescens (Ach.) 

 Tuck. Lecanora fuscata f. sinopica (Wahl.) Nyl. 

 Thallus of pale to dark chestnut, clustered and areolate or scattered and often 

 lobulate squamules; apothecia small to middle-sized, 0.3-0.9 mm. across, immersed 



