R. H. Howe: MANUAL oF THE GENUS USNEA 5 
of fibrils recurved and sorediate (Usnea barbata florida f. sorediifera 
Arn. Flora 57: 569. 1874). 
SupsTRATA : Living deciduous and coniferous trees, specimens 
generally degenerate on other substrata. 
GEOGRAPHICAL DISTRIBUTION: Common throughout North 
America, represented in all zones, and reaching its greatest develop- 
ment and luxuriance in the mountains of Mexico (8000 ft.), and 
becoming rare and poorly exhibited in the upper Boreal zone. It 
is not reported from Labrador, but it is generally recorded from 
Alaska, whence I have seen normal and well-fruited specimens. 
OpsERVATIONS: This plant, Usnea barbata, a florida Fr. of 
Tuckerman, is the most cosmopolitan species of the genus ; both 
its sterile and fertile forms, however, show enormous variation. 
It is nevertheless the typical species of the papillate group and 
makes the most-natural starting point for the taxonomy and an 
understanding of the genus. (‘‘ Typus speciei est forma florida,” 
PreLich Barop. 19). 183%;) 
UsNEA PLIcATA (L.) Web. 
Type: Species based on Usnea vulgaris of Dillenius; the 
“fertile ’’ Dillenian specimen “sufficiently characteristic, though 
. broken up into three portions,” is in the Dillenian herbarium, 
Botanic Gardens, Oxford, England, andis “ Usnea ceratina Ach.” 
fide Crombie. 
Type Locatity: ‘‘ Europae & Americae borealis.” (‘‘ Habeo 
eandem ex Virginia a Jo. Mitchellio et ex Pensylvania a Jo. 
Bartramo transmissam.”’ — Dill. 
ORIGINAL DESCRIPTION: “ Filamentosus pendulus, ramis im- 
plexis, scutellis radiatis,” L. Sp. Pl. 1154. 1753. 
Ficures: [Dill. Hist. Muse. p/. zz. fz. 1741.] Sowerby, 
Eng. Bot. 4: pl. 2. 1795. Ach. Nova Acta Soc. Sci. Upsal. 
7: pl. 7.f. 2. 1815. Schaer. Enum. Crit. Lich. Europ. f/. 7. 
f. 7. 1850. <A. Schneider, Guide Study Lich. p/. 4. 1904. 
Synonymy: [Usnea vulgaris, etc. Dill. loc, cit. 56.] 
Lichen plicatus L. Sp. Pl. 1154. 1753. 
Usnea plicata Web.; Wigg. Prim. Fl. Holsat. 91. 1780. 
Diacnosis: Thallus pendulous, plicate, strongly papillate; short 
rectangularly divergent fidrils sparse or wanting. 
