184 32. PELTIGERACEAE [117. Nephroma 



apothecia small to middle-sized, 1.5-4 mm. across, partly immersed to adnate, the 

 disk deeply concave to rarely flat, chestnut-brown to brownish black, the exciple 

 thin, brownish to colored like the thallus, becoming granulate; hypothecium 

 brownish; asci long-clavate ; spores 4, brown, ellipsoid, 1-septate, 30-50 X 15—22 ju,. 

 On soil, Colorado and Washington. 



3. Solorina crocea (L.) Ach., Vet. Akad. Nya Handl. 228. 1808. 



Lichen croceus L., Sp. PI. 1149. 1753. 



Thallus middle-sized, smooth, lobed, brownish to cinnamon-brown or rarely 

 reddish brown, the lobes more or less imbricated, with wavy margins; bright 

 orange or saffron-colored below with concolorate or brownish branched veins, and 

 bearing few, clustered, brownish rhizoids; apothecia middle-sized to large, 4-10 

 mm. across, adnate, round to irregular, the disk flat to slightly convex, reddish 

 brown to brownish black; hypothecium hyaline to brownish; asci long, cylindrical; 

 spores 8, brown, oblong to fusiform-oblong, 1-septate, 30-44 X 10-14 fx. 



On soil, Montana, Idaho, Washington, Oregon, and Colorado. 



117. Nephroma Ach., Lich. Univ. 101. pi. 11, f. 1. 1810. 



Thallus foliose, small to large, irregularly lobed, more or less closely attached 

 to the substratum by rhizoids, distinctly differentiated into a rather thick, cellular 

 upper cortex, well-developed algal and medullary layers and a thin, cellular lower 

 cortex; apothecia middle-sized to large, marginal or submarginal, adnate or sessile 

 on the under surface of the lobes of the thallus, the disk more or less turned 

 upward, flat, reddish brown to brown, the exciple thin, colored like the thallus, 

 often disappearing; hypothecium hyaline or brownish; hymenium hyaline; paraph- 

 yses unbranched, enlarged, and brownish toward the apices; asci clavate; spores 

 8, brownish to brown, ellipsoid to oblong-ellipsoid or fusiform, 1-3- or rarely 5- 

 septate. 



The algal host is Nostoc or Palmella. 



A. Thallus more or less tomentose below 

 B. Without pits or tubercles below 



C. Lobes large !■ N.arcticum 



C. Lobes small to middle-sized 2. N. helveticum 



B. With pits or tubercles below 



C. Lobes middle-sized to large, margins commonly and 



deeply wavy 3. N. resupinatum 



C. Lobes small to middle-sized, margins crenate 4. N. rameum 



A. Thallus smooth to wrinkled below 



B. Sorediate above, especially toward the margin 6. N. parile 



B. Not sorediate above 



C. Whitish within 5. N.laevigatum 



C. Yellowish within 7. N. lusitanicum 



1. Nephroma arcticum (L.) Torss., Enum. Lich. et Byssac. Scand. 7. 1843. 

 Lichen arcticus L., Sp. PI. 1148. 1753. 



Thallus large to very large, smooth to infrequently more or less undulate or 

 wrinkled, irregularly lobed, the margins round and often undulate, greenish to 

 yellowish straw-colored; black below with paler margins and bearing black rhi- 

 zoids; apothecia large to very large, 4-20 mm. across, adnate, the disk flat, 

 brick-red to reddish brown; spores brownish, oblong-ellipsoid, 3-septate, 20-31 X 

 3.5-5 p.. 



On soil, New England and New York. 



2. Nephroma helveticum Ach., Lich. Univ. 523. 1810. 

 iV. resupinatum f. helveticum (Ach.) Rabh. 



Thallus small to middle-sized, narrowly and deeply lobed, smooth to slightly 

 wrinkled, grayish to yellowish brown, the lobes round, wavy, or irregularly cut, 

 and fringed with toothlike lobules; dark and blackening below and finally to- 

 mentose; apothecia middle-sized to large, 1.5-6 mm. across, the disk flat, reddish 



