274 35. GYROPHORACEAE [134. Gyrophora 



cut-lobate; light brown to dull black and smooth to minutely rough below; apo- 

 thecia small to middle-sized, 0.5-1.5 mm. across, rare, immersed to adnate, round, 

 becoming slightly folded, the disk flat to convex, black, the blackish exciple thin 

 and finally disappearing; hypothecium hyaline to brownish; spores ellipsoid, 12- 



18X6-8/*. „,., . 



On rocks, from New England to North Carolina, and westward to California 



and Washington. 



8. Gyrophora Muhlenbergii Ach., Lich. Univ. 227. pi. 2, f. 11. 1810. 



Umbilicaria Muhlenbergii (Ach.) Tuck. 



Thallus middle-sized to large, smooth, more or less reticulately pitted, some- 

 times becoming perforate, olive-brown, the margin irregularly lobed and com- 

 monly more or less jagged; olive-brown to black, granulose, and reticulated below, 

 with plates of branched or united supporting tissue, infrequently bearing rhizoid- 

 like extensions; apothecia small to middle-sized, 0.5-3 mm. across, round to irreg- 

 ular, adnate, the disk convex, black, becoming closely folded, the blackish exciple 

 soon disappearing; hypothecium brownish or darker; spores oblong to ellipsoid, 

 11-13 X4-5/t. 



On rocks, throughout the northern United States. 



9 Gyrophora proboscidea (L.) Ach., Meth. Lich. 105. 1803. 



Lichen proboscideus L., Sp. PI. 1150. 1753. Umbilicaria proboscidea (L.) 

 Schrad. G. deusta Turn. & Borr. 



Thallus small to middle-sized, reticulately wrinkled, especially toward the cen- 

 ter, blackish brown or rarely grayish pruinose, the margin irregularly scalloped 

 or torn; pale to darker grayish or grayish pruinose, smooth to pitted below, and 

 sometimes bearing scattered black rhizoids; apothecia small to middle-sized, 0.6- 

 1.5 mm. across, adnate, round, becoming much folded, the disk flat to convex, 

 black, the dark exciple thin and finally disappearing; hypothecium brown; spores 

 ellipsoid to oblong-ellipsoid, 12-18 X 6-8.5 /x. 



On rocks, mountains of New England, and westward to Arizona and Wash- 

 ington. 



10. Gyrophora cylindrica (L.) Ach., Meth. Lich. 107. 1803. 



Lichen cylindricus L., Sp. PL 1144. 1753. Umbilicaria cylindrica (L.) Delise. 



Thallus middle-sized, smooth, irregular, gray, varying toward bluish or brown- 

 ish, more or less deeply lobed, the margins commonly fringed with black rhizoids; 

 pale to blackening below and bearing few black rhizoids; apothecia small to mid- 

 dle-sized, 0.6-2.5 mm. across, subsessile to shortly stalked, round, the disk flat to 

 strongly convex, becoming much folded, the margin well developed; hypothecium 

 brown; spores ellipsoid, 10-14 X 6-9 ft. 



On rocks, high elevation, South Dakota and Washington. 



11. Gyrophora rugifera (Nyl.) T. Fries, Lich. Scand. 1:156. 1871. 

 Umbilicaria rugifera Nyl., Not. Sallsk. Faun. Flor. Fenn. 5:117. 1861. 

 Thallus middle-sized to larger, more or less furrowed with coarse, reticulated, 



more or less evident ridges, pale ashy to darker to rarely olive-brown, the margin 

 irregular and sometimes more or less lobed, the lobes often folded together; pale 

 to rosy ash-colored below and more or less covered with short pale rhizoids; 

 apothecia middle-sized to large, 1-4 mm. across, adnate to sessile, round, becom- 

 ing closely folded, the disk flat to convex, black, the dark exciple very thin, 

 becoming flexuous; hypothecium brown; asci becoming ventricose; spores ellipsoid, 

 8-15 X 7.5-8.5/t. 



On rocks, high elevation, California, Oregon, and Washington, and reported 

 eastward to South Dakota and New Mexico. 



12. Gyrophora erosa (Weberi) Ach., Meth. Lich. 103. 1803. 



Lichen erosus Weberi, Spic. Fl. Goett. 259. 1778. Umbilicaria erosa (Weberi) 

 Ach. 



