FINK—THE LICHENS OF MINNESOTA. 209 
Ours at least is uniformly sterile. One plant referred here, no. 716 from Emo, is a 
peculiar form, having larger fibrils and also unusually large soredia. It seems to be 
intermediate between this subspecies and the last above. 
The most common subspecies, and to be looked for on trees in any part of the 
State. 
Found in all parts of North America and Europe. 
1b. Usnea barbata rubiginea Michx. Fl. Bor. Amer. 2:332. 1803. 
Thallus usually quite similar to that of the last, but sometimes more rigid, with 
stouter fibrils, differing in the rusty red color. 
Our specimens are sterile. Acharius mentions the apothecia in Lichenographia 
Universalis. Nylander has not recognized this subspecies so far as the writer can 
ascertain, and it may well be doubted whether a subspecies should. be founded upon 
the variation in color. 
This form has been collected at Minneapolis, Taylors Falls, and Mankato on sand- 
stone, also at Redwood Falls on granite. Is thus confined to the southern half of the 
State and for the most part to sandstone. 
Strictly a North American subspecies. 
le. Usnea barbata ceratina (Ach.) Nyl. Syn. Lich. 1: 268. 1858. 
Usnea ceratina Ach. Lich. Univ. 619. 1810. 
Thallus rather stout and rigid but rather or very long and always pendent, 
branching freely, quite fibrillose, grayish to sea-green; apothecia absent from ours, 
said to be of middle size or even large. 
Common in the northern part of the State, Henning being the most southern Min- 
nesota station known. On trees. 
The subspecies is distributed over all parts of North America, though its distri- 
bution in Minnesota would seem to indicate that it might be a northern form. Widely 
distributed in Europe and also known in Asia and South America. 
1d. Usnea barbata dasypoga Ach. Lich. Univ. 624. 1810. 
Usnea plicata dasypoga Ach. Meth. Lich. 312. 1803.4 
Thallus more slender and lax than in the last, as long or longer and not branching 
so freely, quite as fibrillose and of same color, in foreign specimens sometimes yel- 
lowish. 
Nylander says ‘‘similis floridae, sed thallo clongato pendulo,”’ his brief description 
thus implying characters quite different from those ascribed to the subspecies by 
Acharius in his original description. 
Collected only at Henning and at Rose Lake, but apparently common on trees at 
both localities. Doubtless quite frequent in the northern portion of the State, but 
easily overlooked on account of its close resemblance to the last above. 
Distributed over the northern United States and British America and farther 
south in mountains. Widely distributed in Europe and occurring in Africa and 
Brazil. 
le. Usnea barbata plicata (L.) Fr. Lich. Eur. 18. 1831. 
Lichen plicatus L. Sp. Pl. 1154. 1743. 
Thallus pendent and much elongated, slender and lax, subdichotomously branched, 
paler in color, the fibrils absent or evanescent; apothecia absent in ours, said to be 
small and infrequent. 
The form referred to here seems to be common about Ely, and a specimen was col- 
lected on Flag Island in Lake of the Woods. Not known farther south in the State. 
On trees. 
« Dasypoga was in the original misprinted as dasopoga. 
