134. Gyrophora] 35. GYROPHORACEAE 275 



Thallus middle-sized, minutely wrinkled, becoming reticulated, olive-brown to 

 brownish black, variously open or punctured toward the irregularly torn-lobed 

 margin; brownish to rarely blackening and more or less ridged below, often bear- 

 ing few black rhizoids on the ridges; apothecia small to middle-sized, 0.5-1.2 mm. 

 across, subsessile, round and much folded, the disk flat to convex, black, the 

 black exciple thin and finally disappearing; hypothecium brown; spores ellipsoid, 

 9-12 X 5-7 ix. 



On rocks, Nevada, Montana, Idaho, Washington, and California. 



13. Gyrophora torrefacta (Lightf.) Cromb., Grevillea 12:74. 1884. 



Lichen torref actus Lightf., Fl. Scot. 2:862. 1777. G.erosa var. torrefacta 

 (Lightf.) T. Fries. 



Thallus small, rather thick, rough and furrowed, scarcely or slightly punctured, 

 dark reddish to blackish brown, the margins sometimes slightly torn-lobed; pale to 

 brownish black below, granulate and pitted with few scattered rhizoids; apothecia 

 small to middle-sized, 0.5-1.2 mm. across, infrequent, sessile, round, becoming 

 wavy-folded, the disk flat to convex, black, the dark exciple thin and finally dis- 

 appearing; hypothecium brown; asci becoming inflated; spores ovoid-ellipsoid, 

 9-13 X 6-8 fi. 



On rocks, South Dakota and southern California. 



14. Gyrophora grisea Swartz; Billb. et Swartz, Sven. Bot. 8:546. 1819. 

 Lichen griseus Swartz, Vet. Akad. Handl. 1793:53. 1793. G. hirsuta var. grisea 



(Swartz) T. Fries. 



Thallus small to middle-sized, thin, smooth, minutely powdery, ashy white to 

 pale mouse-colored, the margin sometimes more or less lobed and crenate; ashy 

 to blackish, rough, finely granulose below, or with few black rhizoids; apothecia 

 minute to small, 0.2-0.6 mm. across, adnate, the disk flat to convex, black, becom- 

 ing closely folded, the exciple evanescent; hypothecium brown; spores ellipsoid, 

 13-17 X 7.5-10 ii. 



On rocks, usually at high elevation, Maine and California. 



15. Gyrophora angulata (Tuck.) Herre, Cont. U.S. Nat. Herb. 13:318. 1911. 

 Umbilicaria angulata Tuck., Proc. Am. Acad. 1:266. 1848. 



Thallus small to middle-sized, smooth, irregular, ashy to blackish brown or with 

 a purple or blackish bloom, variously crenate, lobed and torn; black, granulose and 

 more or less covered with paler rhizoids below; apothecia middle-sized to large, 

 1-3.5 mm. across, adnate to subsessile, round to angular, the disk flat to convex, 

 black, becoming closely folded, the exciple thick, rarely disappearing; hypothecium 

 brown; spores ovoid-ellipsoid, 14-22 X 6-11 /x. 



On rocks, Minnesota, Washington, Oregon, and California. 



16. Gyrophora polyrrhiza (L.) Koerb., Par. Lich. 41. 1859. 



Lichen polyrrhizus L., Sp. PL 1151. 1753. G.diabolica Zahlbr. Umbilicaria 

 Muhlenbergii var. alpina Tuck. 



Thallus small to middle-sized, smooth, sometimes deeply lobed, the lobes folded 

 together, greenish copper-colored, the margins irregularly crenate or unequally 

 torn-lobed; black below, reticulated and densely covered with short black rhizoids; 

 apothecia middle-sized to large, 2-7 mm. across, infrequent, immersed to adnate, 

 round to angular or oblong, the disk flat to convex, becoming folded, dark brown to 

 black, the exciple evanescent; hypothecium brownish to brown; spores ellipsoid, 

 8-13 X 4.5-7 fi. 



On rocks, usually at high elevation, South Dakota, Washington, Oregon, and 

 California. 



17. Gyrophora vellea (L.) Ach., Meth. Lich. 109. 1803. 



Lichen vellens L., Sp. PI. 1150. 1753. Umbilicaria vellea (L.) Ach. 



Thallus large to very large, thick, smooth, or rarely rough, variously round to 

 irregular, ashy to ashy brownish, or more or less whitish or bluish pruinose, the 

 margin becoming more or less torn; brown to blackish below, with strong dark 



