Thallus closely adnate at the center with ascending lobes, 5 to 15 cm. in diameter, the upper surface smooth and devoid of trichomatic hyphae for the most part, but the margins sometimes sparingly covered with them, green-gray to brown, the lobes crowded, rather small with crenate, much crisped, elevated margins, the lower surface usually becoming dark brown except at the margins, and thickly reticulated with brown veins, from these numerous rhizoids of similar color extending; medulla of densely interwoven variously disposed hyphae; apothecia numerous on narrow, extending lobes, the disk brown to black-brown, revolute, 4 to 7 mm. in diameter; hypothecium pale brown; hymenium hyaline to pale brown below and dark brown above; asci long-clavate; spores acicular, straight or curved, 4- to 8-celled, 45 to 68 mic. long and 3.5 to 5 mic. wide.
Examined from Butler, Preble, Clark, Adams, and Summit counties. Also reported from Champaign County. On earth and mosses, commonly about trees. Widely distributed in Ohio, but infrequent.
6. Peltigera polydactyla (Neck.) Hoffm. Deutsch. Fl. 2: 106. 1795.
Lichen polydactylon Neck. Musc. 85. 1771.
Thallus adnate at the center with ascendant margins of the lobes, 6 to 11 cm. in diameter, the upper surface smooth and shining, devoid of trichomatic hyphae, the lobes broad with crisped, crenate margins, except those bearing the apothecia, these much narrower and more elongated and usually digitately clustered, brown in color for the most part, the lower surface showing through a reticulation of dark veins as small light-colored spots, numerous dark rhizoids extending downward from the veins; medulla of densely interwoven and irregularly disposed hyphae; apothecia orbicular, and usually revolute, the disk dark brown, 3 to 10 mm. in diameter; hypothecium pale brown; hymenium pale below and dark brown above; asci clavate to cylindrico-clavate; spores acicular, straight or slightly curved, 4- to 6-celled, 42 to 70 mic. long and 3 to 4 mic. wide.
Examined from Clark, Fairfield, and Morgan counties. On earth. Rare in Ohio.
7. Peltigera horizontalis (L.) Hoffm. Deutsch. Fl. 2: 107. 1795.
Lichen horizontalis L. Mant. Pl. 2: 132. 1771.
Thallus mostly adnate, the margins scarcely ascending, 6 to 20 cm. in diameter, the upper surface smooth and shining, devoid of trichomatic hyphae, green-gray to brown, the lobes broad and rounded with entire or crenate margins, the lower surface covered with numerous veins, these giving a dark coloration toward the center and becoming light colored toward the margins, numerous dark rhizoids extending down from the veins; medulla of thick-walled, densely and irregularly disposed hyphae; apothecia on somewhat narrowed lobes, transversely oblong or infrequently orbicular, the disk red-brown, concave, 2 to 4 mm. in diameter; hypothecium light brown; hymenium pale below and dark brown toward the upper surface; asci cylindrico-clavate; spores fusiform to long-ellipsoid, straight to curved, 4-celled, 26 to 40 mic. long and 5 to 6.5 mic. wide. ([Fig. 8] a).
Examined from Lake and Fairfield counties. On earth and mossy rocks. Rare in Ohio.