142. Lecanora ] 38. LECANORACEAE 301 



ing, thinly grayish pruinose, the exciple thick, colored like the thallus, becoming 

 crenate and sometimes disappearing; spores ellipsoid, 10-17 X 5-8.5/*. 

 On rocks, Vermont, Ohio, and California. 



25. Lecanora atrynea (Ach.) Rohl., Deutschl. Fl. 3:82. 1813. 

 L. subfusca var. atrynea Ach., Lich. Univ. 395. 1810. 



Thallus thick, roughly granulose to coarsely warty, chinky to areolate, ashy to 

 grayish white; apothecia small to middle-sized, 0.6-1.5 mm. across, adnate to sub- 

 sessile, the disk flat to slightly convex, lurid brown to black, the exciple thin, 

 colored like the thallus, becoming crenulate and flexuous; spores ellipsoid, 11-16 

 X 6-8 /*. 



On rocks, Minnesota. 



26. Lecanora subfusca (L.) Ach., Lich. Univ. 393. pi. 7, f. 6. 1810. 



Lichen subfuscus L., Sp. PI. 1142. 1753. L.subjusca v&x . allophana Ach. L. sub- 

 ftisca var. discolor (E. Fries) Willey. Parmelia subfusca (L.) Ach. 



Thallus becoming moderately thick, smooth to chinky or warty-areolate, green- 

 ish gray to ashy; apothecia small to middle-sized, 0.5-2.5 mm. across, adnate to 

 sessile, sometimes clustered, the disk flat to somewhat convex, light brown to 

 darker, the exciple thin, colored like the thallus, becoming crenate and rarely 

 flexuous ; spores ellipsoid, 1 1-20 X 7-10 /*. 



On trees or old wood, rarely on rocks or over mosses, throughout the United 

 States. There is much diversity of opinion about the disposition of the subspecies 

 recorded below. 



var. argentata Ach., Lich. Univ. 393. 1810. 

 L. subfusca var. distans (Pers.) Dietrich. L. subfusca var. chlarona Ach. L. chla- 



rona (Ach.) Nyl. 

 Thallus rather thin and smooth, finally somewhat chinky, ashy to white; apo- 

 thecia minute to small, 0.3-1.5 mm. across, the exciple becoming crenulate and 

 rarely disappearing; spores 8-15 X 5-8 /*. 

 On trees, throughout the United States. 



var. campestris Rabh., Deutschl. Krypt. Flora 2:33. 1845. 



Thallus at first granulose, later becoming very thick, rough, and areolate; 

 apothecia becoming strongly and often irregularly convex, the exciple often dis- 

 appearing. 



On trees and rarely on rocks, New England, Maryland, Minnesota, and Cal- 

 ifornia, i 



var. coilocarpa Ach., Lich. Univ. 393. 1810. 



L. coilocarpa (Ach.) Nyl. 



Thallus rather thin, becoming wrinkled and broken, usually whitish; apothecia 

 minute to small, 0.4-1.5 mm. across, the disk black, the exciple usually entire; 

 spores 9-15 X 5.5-9/*. 



On trees and rocks, throughout the United States. 



var. hypnorum (Wulf.) Rabh., Deutschl. Krypt. Flora 2:34. 1845. 

 Lichen hypnorum Wulf., in Jacq., Coll. Bot. 4:233. pi. 7, f. 2. 1790. 

 Thallus running over mosses, rough and granulose, white or whitish. 

 On mosses of high areas, northern Minnesota and Montana. 



var. variolosa Koerb., Syst. Lich. 141. 1855. 

 L. subfusca var. sorediifera T. Fries. L. variolascens Nyl. 

 Thallus warty, becoming more or less whitish sorediate; apothecia few, rather 

 small, the exciple rarely disappearing. 

 On trees, Minnesota. 



27. Lecanora pacifica Tuck., Syn. N. A. Lich. 1:191. 1882. 



Thallus thin, smooth to slightly rough, becoming chinky and areolate, dirty 

 white to grayish; apothecia small to middle-sized, 0.6-1.2 mm. across, adnate to 



