342 40. USNEACEAE [ 158. Alectoria 



exciple soon covered; spores hyaline, short-ellipsoid, 6-9X4-6/*. (Plate 38.) 



On trees, old wood, and soil, throughout the United States, 

 var. implexa (Hoffm.) Ach., Lich. Univ. 593. 1810. 



Usnea implexa Hoffm., Deutschl. Fl. 2:134,135. 1795. 



Thallus shorter, slender, much branched, the branches intertangled, brown. 



On trees, old wood, and soil, throughout northern United States, and south- 

 ward in the mountains. 



3. Alectoria bicolor (Ehrh.) Nyl., Act. Soc. Linn. Bord. 21:291. 1856. 

 Lichen bicolor Ehrh., Plant. Crypt. Linn. Exsicc. 40. 1785. Evernia jubata var. 



bicolor (Ehrh.) E. Fries. A. jubata var. bicolor (Ehrh.) Tuck. 



Thallus rather short, prostrate to erect or rarely hanging, cylindrical, rigid, 

 rarely somewhat sorediate, dichotomously much-branched, the branches more or 

 less fibrillose, brownish black and commonly grayish to yellowish toward the apices; 

 apothecia small, 1.5-3 mm. across, rare, lateral, the disk flat to convex, brownish 

 to dark brown, the exciple disappearing; spores 8, hyaline. 5-9 X 4-6.5 /x. 



On trees, old wood, and soil, Maine and New Hampshire. 



4. Alectoria chalybeiformis (L.) Rohling, Deutschl. Fl. 3 2 : 1 3 7 . 1831. 

 Lichen chalybeiformis L., Sp. PI. 1155. 1753. A. jubata var. chalybeiformis (L.) 



Ach. 



Thallus rather short, spreading to prostrate and rarely hanging, cylindrical to 

 flattened, light to darker brown, densely tufted, rigid, from greenish gray to brown, 

 rather remotely and divergently branched, flexuous, commonly more or less white- 

 sorediate, sparingly fibrillose, especially along the smaller branches, the fibrils 

 frequently several in a cluster; apothecia rare and doubtful, undefined. 



On trees, old wood, and rocks, throughout northern United States, and south- 

 ward in the mountains. 



5. Alectoria Fremontii Tuck., Am. Journ. Sci. II. 25:422. 1858. 



Thallus hanging, reddish brown to black, more or less flattened and lacunose 

 toward the base, sometimes bearing greenish or sulphur-colored soredia, irregularly 

 and remotely much-branched, the branches elongated, round to flattened, smooth, 

 flexuous, much entangled; apothecia small to middle-sized, 2-6 mm. across, the 

 disk flat to convex, yellow-pruinose, the exciple thin, entire, soon covered; spores 

 hyaline, ovoid-ellipsoid, 5-8 X 4-5 /*. 



On branches, mainly of conifers, California, Oregon, Idaho, Wyoming, and 

 Montana. 



6. Alectoria oregana Nyl., Lich. Jap. 104. 1890. 



Thallus of medium length to long, erect to hanging, smooth and shining, green- 

 ish gray to reddish brown and blackening, often paler toward the base and darker 

 above, sparingly to frequently branched, the branches tufted, angulose and con- 

 torted to cylindrical and flattened, slender, tapering toward the round and pointed 

 tips; apothecia small to middle-sized, 2-7 mm. across, lateral and subterminal, 

 sessile, the disk concave to convex, circular to irregular, dark brown, the exciple 

 roughened to tuberculate, dark brown and shining, with short, pointed, spreading 

 or deflexed brown fibrils; spores hyaline, ovoid to subglobose, 5-8 X 3-5 /x. 



On trees, especially conifers, and on old wood, Oregon, Montana, Washington, 

 and California. 



7. Alectoria nigricans (Ach.) Nyl., Not. Sallsk. Faun. Flor. Fenn. 5:71,72. 



1861. 



Cornicularia ochroleuca var. nigricans Ach., Lich. Univ. 615. 1810. 



Thallus long, erect to spreading, chestnut-brown to black, darker above, 

 cylindrical to flattened, becoming rigid, subdichotomously much-branched; apo- 

 thecia middle-sized, 2-4 mm. across, lateral or terminal, the disk concave to con- 

 vex, chestnut-brown, the exciple becoming covered; spores 2-3, hyaline, ellipsoid 

 20-34 X 13-18 /*. 



On soil, Maine and Washington, usually occurring at high altitudes. 



