116. Solorina] 32. PELTIGERACEAE 183 



16. Sticta limbata Ach., Meth. Lich. 280. 1803. 



Stictina limbata (Ach.) Nyl. 



Thallus small to rarely middle-sized, rather loosely attached to the substratum, 

 smooth to becoming reticulately veined and more or less pitted, greenish brown 

 to brown or lead-colored, the lobes broad, with wavy, crenate margins, more or 

 less grayish sorediate toward or along the margins; brownish below, clothed with 

 a soft nap of short rhizoids interspersed with few, concave, whitish cyphellae; 

 apothecia small to middle-sized, 0.6-2 mm. across, scattered, adnate to sessile, the 

 disk flat to convex, dull black, the exciple thin, soon disappearing; spores brown, 

 oblong-ovoid, 1-septate, slightly constricted, 15-22 X 5-8 ju,. 



On trees, Minnesota, Oregon, and California. 



32. PELTIGERACEAE 



Thallus squamulose or foliose, differentiated into well-developed plectenchyma- 

 tous cortex on one or both sides, algal layer and well-developed medulla, cepha- 

 lodia sometimes present and well developed, attached to the substratum by 

 rhizoids; apothecia round to irregular, closely adnate, marginal or scattered on the 

 upper or lower surface of the thallus, without exciple. 



The algal hosts are Palmella, Nostoc, and Dactylococcus. 



A. Thallus with cortex only above; apothecia borne 



on under surface 117. Nephroma 



A. Thallus with cortex above and below; apothecia borne 



on upper surface 



B. Spores brownish to brown 116. Solorina 



B. Spores hyaline 118. Peltigera 



116. Solorina Ach., Vet. Akad. Nya Handl. 228. 1808. 



Thallus foliose, more or less lobed, sometimes squamulose, loosely attached to 

 the substratum by rhizoids, differentiated into a well-developed, thin to thick, 

 plectenchymatous upper cortex, an algal layer, a well-developed medullary layer 

 of interwoven hyphae, and sometimes a poorly developed lower cortex of closely 

 interwoven hyphae; apothecia small to middle-sized or large, partly immersed to 

 adnate, the disk more or less concave to flat or convex, the exciple thin, colored 

 like the thallus, sometimes disappearing; hypothecium hyaline to brownish; hyme- 

 nium hyaline or brownish above; paraphyses unbranched; asci cylindrical; spores 

 2-8, brown, oblong, ellipsoid to fusiform, 1-septate. 



The algal host is Palmella or Nostoc. 



A. Thallus minutely squamulose, passing into a rough crust .... 2. S. spongiosa 



A. Thallus foliose, irregularly lobed, more or less loosely attached 



B. Bright orange or saffron-colored below 3. S. crocea 



B. Grayish to brownish below 1. S. saccata 



1. Solorina saccata (L.) Ach., Vet. Akad. Nya Handl. 228. 1808. 

 Lichen saccatus L., Fl. Suec. ed. 2. 419. 1755. 



Thallus small to middle-sized, smooth, irregularly lobed, rather loosely at- 

 tached to the substratum, greenish gray to ashy or brownish, and rarely whitish 

 pruinose, the lobes rather short, with more or less crenate margins; lighter below 

 and bearing long, scattered rhizoids; apothecia middle-sized, 2-6 mm. across, 

 sunken in the thallus, the disk more or less concave, dark brown, the exciple thin, 

 colored like the thallus, sometimes disappearing; hypothecium brownish; asci 

 cylindrical; spores 4, brown, ellipsoid, 1-septate, 36-60 X 16-24 /*,. (Plate 12 a.) 



On soil and over moss, throughout the United States. 



2. Solorina spongiosa (J. E. Smith) Anzi, Comra. Soc. Critt. Ital. 1:136. 1862. 



Lichen spongiosum J. E. Smith, Engl. Bot. 20: pi. 1374. 1805. S. saccata var. 



spongiosa (J. E. Smith) Nyl. 

 Thallus minutely squamulose, dark green to grayish brown, the squamules sub- 

 erect, minutely lobed and crenate, finally passing into a rough, granulose crust; 



