LICHENS 
I 4 I 
202. Usnea barbata plicata (L.) Fr. 
Lichenplicatus Linnaeus, FI. Suec. 1122. 1755. 
Usnea barbata plicata Fries, L. E. 18. 1831.— Sowerby, Eng. Bot. t. 25 7. 
Alaska (Evans, 255 in part) ; Hot Springs, Baranof Island (Trelease, 
1187). New to Alaska. 
The specimen from Hot Springs is finely developed, though sterile. 
It measures nine centimeters in length and is freely branched. 
I have found record of only one additional form, U. barbata dasypoga 
Fr., collected by Dr. Bean at old Sitka. 
CETRARIA. 
KEY TO THE SPECIES. 
Thallus straw-colored or yellow. 
Thallus depressed, sorediate... .juniperina pinastri. 
Thallus erect, more or less branched, not sorediate. 
Thallus finger-shaped, hollow. arctica. 
Thallus flat, lobed. 
Margins of thallus connivent . cucullata. 
Margins of thallus not connivent.. nivalis . 
Thallus chestnut brown .. ciliaris. 
Thallus variously colored. 
Thallus erect, branching. 
Lobes of thallus connivent. islandica. 
Lobes of thallus not connivent. 
Lobes of thallus narrow, freely branched. islandica delisczi. 
Lobes of thallus broad, moderately branched. 
islandica platyna. 
Thallus flat, lobed. 
Lobes of thallus narrow, elongated, channeled. .fahlunensis. 
Lobes of thallus not channeled. 
Thallus ciliate on the margin, sorediate. 
sccpincola chloropJiylla. 
Thallus not ciliate on the margin. 
Thallus deeply lacunose. lacufiosa. 
Thallus not lacunose . glauca. 
203. Cetraria juniperina pinastri Ach. 
Cetraria juniperma pinastri Acharius, Meth, Lich. 298. 1803. — Hoffm. 
Plant. Lich. /. 7. f. /. 
Alaska (Funston, 4); St. Michael (Setchell) ; Cape Nome (Set- 
chell). New to Alaska, though it has been reported from Arctic 
America by Richardson. 
