288 36. ACAROSPORACEAE [140. Acarospora 



to superficial, 1-several in the areoles, the disk concave to convex, reddish to dark 

 brown, becoming rough and often papillose, the thalloid exciple thin, disappearing; 

 spores subspherical to oblong, 3-5 X 1.8-2.7 fi. 



On rocks other than calcareous, throughout the northern and middle states. 



24. Acarospora glaucocarpa (Ach.) Koerb., Par. Lich. 57. 1859. 



Parmelia glaucocarpa Ach., Meth. Lich. 182. 1803. Lecanora glaucocarpa Ach. 



Thallus of small, pale greenish brown, round, scattered or more rarely clustered 

 and imbricated, entire or crenate squamules; apothecia middle-sized to large, 0.5- 

 1.25 mm. across, 1 or more on each squamule, the disk flat to slightly convex, 

 reddish brown, usually grayish pruinose, the thalloid exciple rather thick, entire; 

 spores oblong-ellipsoid, 4-5 X 1.5-2.5 /a. 



On calcareous rocks, from Vermont to Washington, and southward, 

 f. depauperata (Koerb.) Hazel., Verh. Vere. Nat. Presb. 4:90. 1859. 



A. cervina var. glaucocarpa f. depauperata Koerb., Syst. Lich. Germ. 155. 1855. 



Thallus wanting; apothecia variable in size, scattered or clustered, the disk 

 sometimes pruinose, the thalloid exciple sometimes disappearing. 



On calcareous rocks, Washington, 

 var. verrucosa (Anzi) Magn., Mono. Acar. 240. 1929. 



Lecanora glaucocarpa var. verrucosa Anzi, Lich. Lang. Exsicc. 8:329. 1863. 

 A. glaucocarpa var. distans Am. 



Thallus reduced to minute, scattered, round, convex, greenish brown areoles; 

 the disk of the apothecium only evanescently pruinose. 



On calcareous rocks, Kansas, Texas, and California. 



25. Acarospora glebosa (Flot.) Koerb., Syst. Lich. 156. 1855. 



Zeora cervina var. glebosa Flot., Jahr. Schl. Ges. 122. 1849. Lecanora fuscata 

 var. oligospora (Nyl.) Tuck. 



Thallus of dirty greenish brown, appressed and rounded, scattered or rarely 

 clustered areoles or separate or marginal squamules; apothecia small to middle- 

 sized, 0.4-0.9 mm. across, immersed, 1 in each areole or squamule, the disk concave 

 or flat, reddish brown, the exciple wide, entire or obscurely crenulate, of same 

 color as the thallus; spores oblong-ovoid, 8-15 X 7-10 /*, 20-^10 in each saccate 

 ascus. 



On granite and sandstone, California and Iowa. 



26. Acarospora molybdina (Wahl.) Trevis., Riv. Per. 1st. Padova 262. 1851-52. 

 Parmelia molybdina Wahl., in Ach., Meth. Lich. Suppl. 42. 1803. Lecanora 



molybdina (Wahl.) Ach. Lecanora molybdina var. vulgaris Schaer. A. 

 molybdina var. microcyclos (Ach.) Mass. Lecanora molybdina var. micro- 

 cyclos Ach. 

 Thallus of thick or thin, light to blackish brown, convex squamules, continu- 

 ous and verrucose-areolate toward the center, but linear-lobed toward the margin; 

 apothecia small, 0.4-0.6 mm. across, immersed to semi-immersed, 1 or rarely more 

 in each squamule; the disk concave, brownish black, a thalloid exciple sometimes 

 evident; spores oblong, 3-5 X 1.5-2 p. 

 On rocks, Maine (poorly developed). 



27. Acarospora thamnina (Tuck.) Herre, Bot. Gaz. 55:395,396. 1913. 

 Lecanora cervina var. thamnina Tuck., Syn. N. A. Lich. 1:202. 1882. 

 Thallus of small, branched stipes, rising 10 to 15 mm. high and expanding into 



small, brown to grayish pruinose, closely aggregated, often lobulate and even im- 

 bricate, areole-like areas; apothecia minute to small, 0.2-0.8 mm. across, usually 

 solitary in the areoles, the disk flat, reddish brown, the entire exciple disappearing; 

 spores ellipsoid, 3.3-4.5 X 0.75-1.25 /x. 



On rocks, mountains of California, and eastward to Montana and Nevada. 



OTHER SPECIES REPORTED 

 Acarospora pelioscypha (Wahl.) T. Fries — Nevada. 



