134 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
1. Synechoblastus pycnocarpus (Nyl.) Fink. 
Collema pycnocarpum Nyl. Syn. Lich. 1: 115. 1858. 
Thallus foliose and suborbicular, middle-sized, 15 to 65 mm. in diameter, some- 
times ribbed and here and there perforate, the lobes long and more or less branched 
and rising at the margins into a usually erect position, the erect portions densely 
rugose-lobulate, more or less obscuring the flat parts below, especially when, as at 
length, covered with the apothecia; adhering to the substratum and also attached by 
scattered rhizoids, greenish, olivaceous, or blackish, lighter colored below; algal 
chains distinctly more numerous toward the upper and lower surfaces; apothecia 
small, 0.4 to | mm. in diameter, sessile, the disk brown or reddish brown, becoming 
convex and irregular and sometimes covering the thalloid exciple, this, when present, 
having an entire margin; hypothecium commonly pale; hymenium pale below, and 
pale brownish above; paraphyses simple or rarely branched, commonly enlarged and 
brownish toward the apex; asci clavate; spores 2-celled, ovoid-ellipsoid, 11 to 16 y 
long and 4 to 6.5 # wide. 
Hardly a common Minnesota lichen, but widely distributed in the State. On 
tree trunks. 
Widely diffused in the United States east of the Rocky Mountains and northward 
into Canada. A strictly American plant, known also in South America. 
Collema pycnocarpum of the preliminary reports. 
2. Synechoblastus cyrtaspis (Tuck.) Fink. 
Collema cyrtaspis Tuck. Proc. Amer. Acad. 5: 387. 1862. 
Thallus quite similar to that of the last, but on the whole larger and more distinctly 
lobed, the coloration as above; apothecia said to be larger, reaching 2 mm. in 
diameter, and more scattered, the thalloid margin more persistent and commonly 
crenulate; spores 4-celled. 
It is the last character which more than any other seems to separate the species 
from the last above. 
Determined from Vermillion Lake by H. Willey. On tree trunks. We have not 
examined the plant microscopically. 
Quite widely distributed throughout the eastern half of the United States and 
northward into Canada. Not known elsewhere. 
Collema cyrtaspis of the preliminary reports. 
3. Synechoblastus flaccidus (Ach.) Trev. Caratt. Gen. Collem. 1853. 
Lichen flaccidus Ach. Vet. Akad. Handl. 16: 14. 1795. 
Thallus foliose and suborbicular, middle-sized, 2 to 7 cm. in diameter, some- 
what more loosely attached to the substratum than other species (disregarding, of 
course, the erect lobes of the last two species), and scarcely so gelatinous when 
wet as the two above; composed of rather wide, rounded, entire lobes, these more 
or less imbricate and clothed frequently with granules of the same color as the thallus, 
the color above olivaceous, commonly varying toward black and less frequently 
toward greenish, usually lighter below; rhizoids few and weak and the plants more 
usually adhering to the rocks; algal cells slightly more numerous toward the upper 
surface; apothecia small and sessile, seldom present in ours, 0.5 to 1 mm. in diameter, 
the disk reddish brown, flat or convex, the margin entire and frequently granulate; 
hypothecium pale to brownish; hymenium pale below and brownish yellow above; 
paraphyses simple or rarely branched, the apices usually enlarged and brownish; 
asci clavate; spores 4 to 6-celled, fusiform-oblong, 20 to 26 « long and 6 to 8 » wide. 
Generally distributed over the State, but not common anywhere. On trees and 
rarely on rocks. 
Widely distributed in North America. Common also throughout Europe, 
Collema flaccidum of the preliminary reports, 
