386 44. PHYSCIACEAE [ 174. Physcia 



7. Physcia endochrysea (Hampe) Nyl., Flora 58:442. 1875. 



Parmelia endochrysea Hampe, in Nyl, Syn. Lich. 1:427. 1858. P.obscura var. 

 endochrysea (Hampe) Nyl. P. obscura f. endococcinea (Koerb.) T. Fries. 



Thallus small to middle-sized, adnate, smooth to slightly rough, greenish gray to 

 brownish, sometimes sorediate, saffron-colored within, the lobes becoming elon- 

 gated and branched, often imbricated, the margins round to crenate; black below 

 with black rhizoids; apothecia middle-sized to large, 0.5-3 mm. across, sessile, the 

 disk concave to flat, reddish brown to black, the exciple entire to crenulate, more 

 or less hispid, at least below; spores oblong-ellipsoid, 14-22 X 7-10 /x. 



On trees and rocks, from New England to Alabama, and westward to Texas 

 and Minnesota. 



8. Physcia lithotodes Nyl., Flora 58:360. 1875. 

 P.lithotea var. lithotodes (Nyl.) Lynge. 



Thallus small, adnate, irregular, greenish gray to brownish, the lobes short, 

 much branched, imbricated, with ragged, digitate margins; blackish below and 

 densely covered with black rhizoids; apothecia minute to small, 0.5-2 mm. across, 

 sessile, the disk flat, black, the exciple thin to moderately thick, colored like the 

 thallus, becoming wavy and flexuous, with or without fibrils below; hypothecium 

 hyaline; spores ellipsoid, 15-23 X 6-10 ^u. 



On trees, Maine and New York. 



9. Physcia setosa (Ach.) Nyl., Syn. Lich. 1:429. 1860. 

 Parmelia setosa Ach., Syn. Meth. Lich. 203. 1814. 



Thallus middle-sized, adnate, greenish gray to ashy, the lobes elongated, much 

 branched, sometimes imbricated, with entire to wavy margins, sometimes passing 

 toward the center into a crust of closely packed and imbricated lobules; black 

 below, resting on and bordered by strong black rhizoids; apothecia small to middle- 

 sized, 2-5 mm. across, sessile, the disk more or less deeply concave, reddish brown, 

 the exciple entire or subentire, hispid; spores oblong-ellipsoid, 20-30 X 10-15 p. 



On soil, rocks, and trees, from New England to New York, thence westward 

 to Ohio and New Mexico. 



10. Physcia stellaris (L.) Nyl., Syn. Lich. 1:424. 1858. 



Lichen stellaris L., Sp. PL 1144. 1753. P. stellaris var. aipolia (Ehrh.) Hampe. 



Thallus middle-sized, adnate, greenish gray to whitish or brownish, the lobes 

 rather narrow, frequently elongated, much branched, sometimes imbricated, the 

 margins entire to crenate, often passing centrally into a crust; white below with 

 white rhizoids, or sometimes becoming darker to black with rhizoids of the same 

 dark color; apothecia small, 2-4 mm. across, sessile, the disk slightly concave to 

 convex, whitish pruinose to dark brown or black, the exciple entire to crenate; 

 spores oblong-ellipsoid, 14-24 X 8-11 [x. (Plate 47 a.) 



On trees and rocks, throughout the United States (usually becoming dark below 

 when growing on rocks). 



var. leptalea (Ach.) Nyl., Syn. Lich. 1:425. 1858. 

 Lichen leptaleus Ach., Lich. Prod. 108. 1798. 

 Thallus narrowly lobed and ciliate at the margins. 

 On trees, California. 



11. Physcia venusta (Ach.) Nyl., Syn. Lich. 1:421. 1858. 



Parmelia venusta Ach., Syn. Meth. Lich. 214. 1814. P . pulvendenta var. sitb- 

 venusta Nyl. 



Thallus small to middle-sized, closely adnate, greenish gray to tawny brown, 

 the lobes long, narrow, much branched with round to crenate, sometimes grayish 

 pruinose margins, the inner lobes often marked with small toothlike lobules; black 

 below or paler toward the margins, and densely covered with black rhizoids; apo- 

 thecia minute to small, 0.5-1.5 mm. across, sessile, the disk flat, reddish black to 

 black, often gray or bluish pruinose, the exciple thick, colored like the thallus. 





