8 R. H. Howe: MANvuAL OF THE GENUS USNEA 
larly divergent equiform fibrils. These secondary branches taken 
alone strongly suggest U. dongissima, but are generally somewhat 
papillate or papillo-sorediate, and not covered with a white fari- 
naceous soredial crust. Dillenius’ figure shows a characteristic 
intermediary condition, some of the secondary branches suggesting 
the species U. plicata, while the majority are nearly typical of the 
present subspecies. This intermediary state is not uncommon, a 
specimen from Newfoundland (Waghorne, 1890, called U. dongts- 
sima) in the herbarium of the Academy of Natural Sciences, Phila- 
delphia, almost exactly duplicates the subject of Dillenius’ figure, 
showing the unusual dichotomously branched fibrils. 
Thallus epapillate 
UsNEA TRICHODEA Ach. 
Type: Not indicated, but the specimen on which the species 
was based is in the Acharian herbarium, Universitetets Botaniska 
Institution, Helsingfors, fide Prof. Dr. Fred. Elfring, 7 /¢z., Apr. 
7, 1909. 
Type Locatity: ‘* Nova Scotia” [‘‘ Menzies,” fide Elfring]. 
ORIGINAL DESCRIPTION: ‘‘Thallo subcrustaceo filamentoso 
tenerrimo tereti diffuso albo-pallescente, lorulis capillaceis ramosis 
fibrillis subsecundis ; orbillis concoloribus margine tenui inflexo 
nudo integro,” Ach. Meth. Lich. 2: 312. 1803. 
Figure: Ach. /oc. cit. pl. 8. f. 3. 
Synonymy: Usnea trichodea Ach. loc. cit, 2: 312. 1803. 
Diacnosis: Thallus pendulous, glabrous, fibrils capillaceous. 
DEscRIPTION — typical: Zhal/us pendulous, slender, mollitin- 
ous, terete, virescent, cortex g/adrous or nitidous, annularly scarred, 
at length bambusaceous; primary branches slender, at length 
proximally scabrous, much divided (max. length 25 cm.) ; second- 
ary branches subdichotomous, much divided; fiéri/s capillaceous, 
tortuous. Afpothecta common, marginate, at length lacerate, lateral, 
sessile, small (diameter 4 mm.), disk flesh-colored or buff, margins 
naked or sparsely ciliate. Spores 4-8 uw x 3-6 p. 
CONTINGENT PHASES: (@) Asin U. plicata. - 
(4) Cortex now locally ruptured by soredia. 
SUBSTRATA: Coniferous trees, frequently on dead wood, and 
occasionally on accompanying deciduous trees. 
