140 CUMMINGS 



ous mosses. The specimen from Agattu Island is the best developed 

 and shows no intermixture of other lichens. All the specimens are 

 sterile. A common arctic form. 



The only additional Alaskan species of which I find record is A. 

 fremontii Tuck., collected by Dr. Cooley at Sitka and at Salmon 

 Creek, near Juneau. 



USNEA. 



KEY TO THE SPECIES. 



Thallus short, tufted. 



Thallus fine, nearly smooth harhata. 



Thallus coarse, papillate barbata Jlorida. 



Thallus elongated, pendulous. 



Thallus profusely subdichotomously branched, without spreading 



fibrils barbata flicata. 



Thallus scarcely branched, covered with spreading fibrils, very much 

 el onga t ed lo ngiss ima . 



199. Usnea longissima Ach. 



Usnea longissima Acharius, L. U. 626. 18 10. 



Alaska (Dr. Kellogg, 6 ; Evans, 255 in part) ; Fort Cosmos (Huff, 

 a)\ Sitka (Setchell, 1259 in part, 1262, 1264); Broughton Strait 

 (Trelease, 1 1 84) . Tuckerman records it as having been collected in 

 Russian America by Dr. Kellogg. 



The specimen collected by Mr. Evans has with it Cetraria glauca^ 

 Alectoria jubata^ Parmelia physodes and U. barbata pltcata. No. 

 1259, collected by Professor Setchell at Sitka, is mixed with Alectoria 

 Jubata. With the specimen from Broughton Strait is the following 

 note : *' Strangling evergreens close to the seaside." Mixed with the 

 specimen are fragments of Alectoria and of species of Dicranum and 

 Polytrichum. 



200. Usnea barbata Fr. 



Usnea barbata Fries, Sched. Crit. 9: 34. 1 824-1 833. 



Eraser Reach (Coville and Kearney, 301) ; Broughton Strait, Van- 

 couver Island (Trelease, 1184c), with Usnea longissima. Both 

 specimens sterile. Collected by Dr. Bean, but no definite locality 

 given. 



201. Usnea barbata florida (L.) Fr. 



Lichen floridus 'Li'nyiJE.vs, Fl. Suec. 1130. 1755. 



Usnea barbata florida Fries, L. U. 18. 1831. — Sowerby, Eng. Bot. /. 872. 



Sitka (Trelease, ii8o($). A very much dwarfed, sterile specimen, 



which would seem best placed here. New to Alaska. 



