visible, or convex when the exciple often becomes covered; hypothecium
brown to black-brown; hymenium pale or tinged brown; paraphyses
distinct, but sometimes coherent; asci clavate; spores oblong-ellipsoid,
brown, 4-celled to muriform, 12 to 22 mic. long and 4 to 9 mic. wide
(Fig. 8), 8 in each ascus.

Collected in Butler, Preble, Ross, and Highland counties. On bark,
especially elm bark. Also reported from Ottawa County. Rare but
doubtless distributed widely in the State.


3. Rhizocarpon petraeum (Wulf.) Koerb. Syst. Lich. 260. 1855.

_Lichen petraeus_ Wulf. in Jacq. Coll. Bot. 3: 4. pl. 6. f. 2a. 1789.

Thallus an ash or green-gray crust, or varying toward brown or
brown-black, smooth to more commonly roughened, chinky to areolate,
continuous or scattered, of moderate thickness, often widely and
irregularly disposed on the substratum; apothecia small to large, 0.5 to
1.3 mm. in diameter, immersed to adnate, black-brown to black, flat with
the concolorous exciple visible, or becoming somewhat convex, with the
exciple often covered; hypothecium dark brown; hymenium pale, or tinged
brown, especially above; paraphyses coherent, semi-distinct; asci
clavate or inflated-clavate; spores oblong-ellipsoid, 4-celled to
muriform, hyaline to finally brown, 15 to 40 mic. long and 7 to 18 mic.
wide. 8 in each ascus (Fig. 9).

Collected in Lake, Hocking, and Ross counties. Also examined from
Summit, Vinton, and Ashtabula counties. On rocks. Rare but widely
distributed in the State.