118. Peltigera ] 32. PELTIGERACEAE 185 



brown to brown, the exciple thin, colored like the thallus, becoming wavy; spores 

 brown, 3-septate, ellipsoid to subfusiform, 15-22 X 5-8. 5 tt. 



On trees and rocks and over mosses, throughout the United States. 



3. Nephroma resupinatum (L.) Ach., Lich. Univ. 522. 1810. 



Lichen resupinatus L., Sp. PI. 1148. 1753. N.tomentosum (Hoffm.) Flot. 



Thallus middle-sized to large, smooth to more or less tomentose, greenish gray 

 to lead-colored or brown, the lobes round, with margins commonly and deeply 

 waved; whitish below, brownish tomentose, and bearing minute whitish tubercles; 

 apothecia middle-sized to large, 2-12 mm. across, the disk reddish brown, the 

 exciple colored like the thallus, becoming irregularly crenate; spores brownish, 3- 

 rarely 5-septate, fusiform to oblong, 19-26 X 4.5-7 fx. 



On trees, throughout northern United States. 



4. Nephroma rameum (Schaer.) Mass., Mem. Lich. 23. 1853. 



N. resupinatus f. rameum Schaer., Enum. Lich. Eur. 18. pi. 2, f. 3. 1850. Ne- 

 phromium tomentosum var. rameum (Schaer.) Nyl. 



Thallus small to middle-sized, smooth to minutely granulose, finally imbricated, 

 greenish gray to grayish brown, the lobes irregular with crenate margins; brown- 

 ish below, and sometimes bearing whitish tubercles and pits; apothecia middle- 

 sized to large, 2-7 mm. across, borne on the margins of the lobes, the disk flat, 

 reddish to dark brown, the exciple thin, colored like the thallus, becoming wavy; 

 spores brownish, oblong, 3-septate, 17-24 X 6.5-8.5 /x. 



On trees, Washington and California. 



5. Nephroma laevigatum Ach., Syh. Meth. Lich. 242. 1814. 



Thallus small to middle-sized, with small, roundish lobes, smooth to finely 

 wrinkled and pitted, marginally crenate and wavy, greenish gray to chestnut- 

 brown; wrinkled and naked, and white or whitish below, or rarely tinged with 

 brown; apothecia middle-sized to large, 2-5.5 mm. across, adnate, the disk flat, 

 reddish to dark brown, the exciple thin, colored like the thallus; spores brownish, 

 fusiform-ellipsoid, 3-septate, 16-23X4-7 fi. 



On trees and rocks, throughout northern United States and in California. 



6. Nephroma parile Ach., Lich. Univ. 522. 1810. 



Lichen parilis Ach., Lich. Suec. 164. 1798. N. laevigatum f. parile (Ach.) Mudd. 



Thallus small to middle-sized, smooth, becoming sorediate, greenish gray to 

 chestnut-brown, the lobes round, curled, strongly grayish sorediate toward the 

 margin; wrinkled and blackening below; apothecia middle-sized to large, 2-4.5 mm. 

 across, borne on the margins of the lobes, the disk flat, reddish brown to dark 

 brown, the exciple very thin, colored like the thallus; spores brownish, fusiform- 

 ellipsoid, 3-septate, 16-24 X 5-6 /t. 



On trees, New England, New York, Minnesota, and Montana. 



7. Nephroma lusitanicum Schaer., Enum. Lich. Eur. 323. 1850. 

 Nephromium lusitanicum (Schaer.) Nyl. 



Thallus small to middle-sized, smooth to more or less reticulately wrinkled, 

 slightly to deeply lobed, with crenate margins, greenish gray to chestnut-brown, 

 yellowish within; smooth to finely wrinkled below, and pale to brown or darker; 

 apothecia middle-sized to large, 2-5 mm. across, borne on the margin of the lobes, 

 the disk flat, reddish brown to chestnut-brown; spores brownish, 3-septate, fusi- 

 form-oblong, 19-24 X 5-8 ii. 



On trees and rocks, Maine, Washington, Oregon, and California. 



118. Peltigera Willd., Fl. Berol. Prod. 347. 1787. 



Thallus foliose, usually large, more or less lobed, rather loosely attached to the 

 substratum, differentiated into a well-developed, cellular upper cortex, a distinct 

 algal layer, and a medullary layer with horizontal hyphae below bearing numerous 

 rhizoids, more or less veined below, the upper surface sometimes more or less 



