The Collemaceae of Ohio 
.■)0 
surface lighter colored, similarly wrinkled, and more or less pitted, with 
the lobes rounded and sometimes imbricated, with entire or undulate 
margins, and with the algal chains more numerous toward the surfaces, 
especially the upper; medulla of scattered hyphse, which are in part 
irregularly arranged and in part perpendicular to the surfaces, the latter 
arrangement more noticeable toward the margins, 1.75 to 2.6 mic, wide, 
and slightly more numerous toward the upper surface; cells of the upper 
cortex 4 to 8 mic. long and 4 to 7.5 mic. wide, those of the lower cortex 
distinctly smaller, the cortex several cells thick around the apothecia; 
rhizoids rarely seen in the sections; apothecia common, small to middle- 
sized, 0.5 to 2 mm. in diameter, sessile or raised on a pseudostipe, and 
surrounded by a thalloid margin; disk flat and light- or darker-brown; 
exciple plectenchymatous; hypothecium plectenchymatous below, of inter¬ 
woven hyphse above, 90 to 140 mic. thick; hymenium 80 to 105 mic. 
thick; spores ellipsoid to ellipsoid-pointed, longitudinally 6-celled, trans¬ 
versely 2- to 4-celled, 18 to 33 mic. long and 9 to 16 mic. wide. See Figs. 
1, 3, 5, and 13. 
Generally distributed over the state, but not common. On the 
trunks of trees, and rarely on rocks. Examined from areas about 
Peebles, Washington C. H., Springfield, Paint, Cedar Swamp, George- 
ville. Sugar Grove, Chester Hill, and Columbus. 
2. Leptogium lacerum (Retz.) S. F. Gray, Xat. Arr. Brit. PI. i: 401. 
1821. 
LicJicn laccr Retz. FI. Scand. Prodr. 228. 1774. 
Transforming the algal-host colony into a middle-sized, suborbicular 
or irregular body, which is 1.5 to 7 cm. across, 60 to 210 mic. thick, and 
reticulately wrinkled, with the closely adnate horizontal portions obscured 
by ascending and expanding lobes, with the margins sinuate or more often 
finely jagged and lacerately fringed, with the upper surface lead-colored 
to olive-brown, with the lower surface scarcely lighter colored, and with 
the algal chains more numerous toward the upper surface; medulla of 
densely disposed and uniformly distributed hyphae, which are 2.6 to 
5 mic. wide and extend in various directions; cells of the upper cortex 
8 to 13 mic. long and 11 to 13 mic. wide, those of the lower cortex 
scarcely differing in size; cortex rarely thickened to two layers of cells 
around and below the apothecia; rhizoids rarely seen in the sections; 
apothecia rare, small to middle-sized, sessile, 0.4 to 1.5 mm. in diameter; 
disk flat or concave, red-brown, surrounded by a thalloid margin, which 
