210 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Distributed over the northern part of the United States and over Alaska and 
British America, and farther south in the mountains. Also widely distributed in 
Europe and found in South America, 
2. Usnea angulata Ach. Syn. Lich. 307. 1814. 
Thallus fruticose, rather stout and rigid but much elongated and pendent, the main 
trunk at least more or less angulate and lacunose, branched rather remotely, at least 
toward the ends, thickly covered with rather long pointed fibrils, grayish to sea- 
green in color, 6 to 25 cm. long; apothecia absent from ours, but said to be small 
with flesh-colored disk bearing a white bloom, ‘Spores rounded-ellipsoid, 5 to 8 It 
long and 4.5 to 5.5 » wide.”” Other microscopic data not obtainable. 
A single specimen has been collected in the State, viz, by Macmillan on a tama- 
rack in a swamp near Minneapolis. . 
Widely distributed in the United States east of the western Cordilleras, and also 
frequently reported from South America. Otherwise only known on certain islands 
of the Southern Hemisphere. 
3. Usnea longissima Ach. Lich. Univ. 626. 1810. Puate 42, B. 
Thallus fruticose, varying in length from 10 to 150 cm., or even longer, the 
point of attachment to the substratum seldom to be found, the plants usually hanging 
free over the branches of trees, cylindrical or somewhat compressed, roughened, ours 
quite slender and lax, though other specimens are usually stouter, rather sparingly 
branched, clothed with usually long fibrils, these commonly horizontal and rather 
straight, light or darker sea-green; apothecia said to reach middle size, but small 
and terminal in specimens at hand, 1 to 2.5 mm. in diameter, the disk pale flesh- 
colored and concave, the margin bearing long fibrils; hypothecium pale; hymenium 
_pale or brownish; paraphyses simple or branched, with pale but somewhat thickened 
apices; asci clavate to cylindrico-clavate; spores oblong-ellipsoid, 9 to 10 long and 
4 to 5 wide. 
Ours uniformly sterile, the above microscopic features of the apothecia taken from 
Arnold’s European Exsiccati, no, 1685a. 
Frequent along the north shore of Lake Superior and rarely occurring back from 
the shore near the northern boundary. On trees. 
Distributed throughout northern United States, Alaska, and British America, 
especially in the mountains. Occurring in all the grand divisions. 
EXPLANATION OF PLATE 42.—See p. 207. 
4. Usnea cavernosa Tuck. in Agassiz, Lake Superior 171. 1850. PLATE 43. 
Thallus pendent, elongated, 10 to 35 cm. long, the basal enlarged portions often 
reaching 3 to 5 mm. in diameter, compressed-cylindrical or angulate, foveolate- 
lacunose toward the large basal portions of the main stems, rather sparingly branched 
below but much dichotomously branched above, the branches finally very small and 
much interwoven; scarcely fibrillose or the basal enlarged and somewhat compressed 
portions of the main trunks occasionally quite fibrillose, especially along the margins; 
light or darker sea-green; apothecia small to middle-sized, 1 to 6.5 mm. in diameter, 
seldom terminal; the disk pale flesh-colored and concave; the margin, in ours at least, 
quite strongly fibrillose with long fibrils; hypothecium pale; hymenium pale through- 
out; paraphyses somewhat distinct, simple or branched, with pale, thickened apices; 
asci clavate; spores ellipsoid or short-ellipsoid, 7 to 9 4 long and 4 to 5 » wide in ours, 
The plant is frequently found in the northeastern one-third of the State. On 
trees. Tuckerman’s statement that the plant strongly resembles Alectoria ochroleuca 
sarmentosa Nyl. is well founded. 
Distributed widely in British America, but in the United States confined for most 
part to mountainous regions. Also known in southern South America and in India. 
EXPLANATION OF PLATE 43.—A spruce covered with Usneas and Alectorias, for the most part Usnea 
cavernosa, at Grand Portage. About one-thirteenth natural size. 
