IRbodora 
JOURNAL OF 
THE NEW ENGLAND BOTANICAL CLUB 
Vol. 7 May, 1905 No. 77 
THE NORTH AMERICAN SPECIES OF ERIOPHORUM. 
M. L. FERNALD. 
PART 1. SYNOPSIS OF AMERICAN SPECIES. 
THE genus Eriophorum, familiarly known as Cotton Grass, is gen- 
erally distributed in the boreal regions of the northern hemisphere ; 
and on account of its conspicuous perianth the genus is perhaps 
more quickly recognized by the general student than other members 
of the Cyperaceae. In spite of this comparative ease of recognition, 
or perhaps because of it, the genus, as understood in America, has 
come to be one with ill-defined botanical limits, and not sharply sep- 
arated from some sections of the genus Scirpus; while its species as 
ordinarily interpreted in American floras are in an unfortunate state 
of confusion. A prolonged study of the material in the Gray Her- 
barium and the herbarium of the New England Botanical Club, 
supplemented by the very extensive collections of the Geological 
Survey of Canada, generously loaned by Mr. J. M. Macoun, and the 
material in several private herbaria, has led the writer to prepare the 
following synopsis of the American species. This synoptic treat- 
ment will be followed by a detailed discussion of the history and 
some of the affinities of the genus /riophorum, with notes on certain 
species which have been misinterpreted in past treatments of the 
group. In the bibliography of this work the writer has been greatly 
assisted by Miss Mary A. Day. 
SYNOPSIS OF SPECIES. 
$ VAGINATA, Andersson, Cyp. Scand. 13 (1849). Spikelet 
solitary, without involucral leaves ; the lowermost scale usually en- 
