48 
Ohio Biological Survey 
3. Synechoblastus nigrescens (Muds.) Stizenb. Rer. St. Gall. Ges. 
Naturw. 1861 - 1862 : 144. 1862. 
Lichen nigrescens Huds. FI. Angl. 450. 1762. 
Transforming the algal-host colony into a middle-sized, orbicular or 
irregular foliose body, which is 2 to 7 cm. across, 60 to 185 mic. thick, 
and closely adnate, with the upper surface closely beset with pustules, 
on many of which apothecia are situated, or with the pustules largely 
replaced by radiating ridges, with short, rounded, entire, and usually 
somewhat raised lobes, with the upper surface olive-green and blacken¬ 
ing, with the lower surface lighter colored and marked by depressions 
which correspond with the pustules or the ridges of the upper surface, 
and with the algal chains somewhat more numerous toward the upper 
surface; thallus of hyphse which are densely disposed, somewhat uni¬ 
formly distributed with course largely perpendicular or horizontal, and 
1 to 2.5 mic. wide; rhizoids rarely seen in the sections; apothecia rather 
small, numerous, sessile, crowded toward the center of the thallus, which 
is sometimes obscured by them, 0.4 to 1.2 mm. in diameter; disk flat or 
convex, brown or red-brown and surrounded by a thin thalloid margin, 
which is sometimes overgrown; exciple plectenchymatous, tinged with 
brown; hypothecium plectenchymatous below, of interwoven hyphse 
above, 40 to 65 mic. thick; hymenium 85 to 115 mic. thick; paraphyses 
sometimes anastomizing by a bridge; asci 65 to 85 mic. long and 14 to 
22 mic. wide; spores 4- to several-celled, long-fusiform to acicular, 40 
to 70 mic. long and 3.5 to 6.5 mic. wide. See Figs. 12 and 13. 
Known in Ohio only through specimens collected by T. G. Lea near 
Cincinnati, in 1841. However, the plant should occur in other portions 
of the state. On the trunks of trees. 
4. Synechoblastus ryssoleus (Tuck.) Fink Cont. U. S. Nat. Herb. 14 ^: 
135. 1910. 
Collema nigrescens ryssoleum Tuck. Lich. Calif. 34. 1866. 
Transforming the algal-host colony into a rather small, suborbi- 
cular, foliose, membranaceous body, which is 2 to 5 cm. across, 60 to 200 
mic. thick, and rather smooth, with rounded, ascending lobes, with pli¬ 
cate, undulate and crisped margins, with the upper surface olivaceous to 
black-brown and rugose-papulose, with the lower surface lighter colored 
and reticulate, and with the algal chains somewhat more numerous 
toward the surfaces; thallus of densely disposed hyphge, which are more 
