118. Peltigera ] 32. PELTIGERACEAE 187 



toothed and disappearing; hypothecium brownish to rarely brown; spores fusi- 

 form, brownish to hyaline, 3- rarely 4-septate, 28-45 X 6-9 [x. (Plate 12 b.) 

 On soil, throughout the United States. 



3. Peltigera horizontalis (Huds.) Baumg., Fl. Lips. 562. 1790. 

 Lichen horizontalis Huds., Fl. Angl. 453. 1 762. 



Thallus middle-sized to large, somewhat closely adnate, smooth and shining, 

 greenish gray to ashy or reddish brown, the lobes broad and ascending with round 

 to irregular margins; white below, reticulated with blackening veins passing into 

 a continuous close nap; apothecia middle-sized, 3-5 mm. across, borne on nar- 

 rowed lobules or submarginal, sometimes superficial, horizontal, the disk reddish 

 brown, transversely oblong, the exciple becoming subcrenulate; hypothecium 

 brownish; spores hyaline to pale brownish, 3-septate, long-ellipsoid, 30-48 X 

 5-7.5 fi. 



On soil and over mossy rocks, throughout the United States. 



4. Peltigera Zopfii Gyelnik, Bot. Kozlem 24:134, 135. 1927. 



Thallus middle-sized to large, rather closely adnate, smooth and shining to 

 bearing isidia along the ascending, irregular margins of the broad lobes, greenish 

 gray to ashy or rarely reddish brown; white or whitish below, reticulated with 

 few to many brownish to brown veins bearing few brownish rhizoids; apothecia 

 middle-sized, 2-5 mm. across, borne on narrowed lobules, adnate, horizontal, the 

 disk flat to convex, dark brown; hypothecium yellowish to brownish; spores hya- 

 line, oblong, straight or curved, 3-septate, 40-45 X 6-6.5 p.. 



On soil, Connecticut. 



Very close to Peltigera horizontalis but separated by the isidioid margins of 

 the upper surface of the thallus and fewer veins and rhizoids of the lower. De- 

 scription compiled. 



5. Peltigera polydactyla (Neck.) Hoffm., Descript. & Adumbr. PI. Lich. 1:19, 



20. pi. 4, f. 1. 1790. 



Lichen polydactylon Neck., Meth. Muse. 85. 1771. 



Thallus middle-sized to large, closely adnate, smooth and shining, greenish 

 gray to lead-colored and brownish, the lobes broad and variously irregular, ascend- 

 ing toward the margins; whitish to blackening below, reticulated with brownish to 

 blackened veins, and bearing small to large, brownish to black rhizoids; apothecia 

 middle-sized, 3-5 mm. across, borne on narrow, extended, digitately clustered 

 lobules, commonly rolled backward, the disk reddish to dark brown, the exciple 

 becoming irregularly crenulate; hypothecium brownish; spores hyaline, 3-7-septate, 

 acicular, sometimes slightly curved, 60-100 X 3-4 /jl. 



On soil, widely distributed throughout the United States. 



o. Peltigera scutata (Dicks.) Duby, Bot. Gall. 2:599. 1830. 



Lichen scutatus Dicks., Fasc. PI. Crypt. Brit. 3:18. 1793. P. polydactyla var. 

 scutata (Dicks.) E. Fries. 



Thallus rather thin, small to middle-sized, adnate, bearing scattered trichomatic 

 hyphae, sinuately lobed, greenish gray to ashy or brownish, ascending toward the 

 irregular, often isidioid-granulose to sorediate margins; brownish to dark brown 

 below, with many brown veins; apothecia small to middle-sized, 2-5 mm. across, 

 borne on short lobules, round to oblong, sometimes rolled backward, the disk 

 reddish brown, the margin inflexed and soon crenate; hypothecium brownish; 

 spores hyaline, 3-7-septate, acicular, 48-68 X 3-4.5 /x. 



On trees and soil, widely distributed throughout northern United States. 



7. Peltigera malacea (Ach.) Funck, Crypt. Gewach 33. Heft. 5. 1827. 



Peltidea malacea Ach., Syn. Lich. 240. 1814. 



Thallus loosely adnate, middle-sized to large, somewhat soft and spongy, finely 

 granulose or rarely downy, greenish gray to ashy or rarely brownish, with narrow, 

 round, or wavy lobes, usually ascending toward the margins; brownish to blackish 



