140 Rhodora |JuLy 
Along the parts of Big Stone and Traverse Lakes visited, S. missouri- 
ensis was practically the only species of the cordata group present. 
A single plant of cordata was found at a large spring beside the Sisseton 
road about 2 miles northwest of Brown’s Valley, Minn., and near 
the south end of Lake Traverse. In the coulees of the Sisseton Hills, 
however, some 12-15 miles to the northwest, at elevations several 
hundred feet higher, S. missouriensis was associated with S. lutea 
Nutt., the latter species being fairly common there. 
Salix missouriensis Bebb differs from S. cordata Muhl. chiefly in 
the larger size, the more densely pubescent or tomentose one-year 
branchlets, the densely tomentose or pilose bud-scales, pubescent 
petioles, and the ‘usually larger leaves, more distinctly glaucous 
underneath, with midveins pubescent in the basal portion of the leaf 
both above and below. The furry bud-scales are especially striking 
at nearly all seasons of the year. A dense coma occurs at the base 
of the aments and newly developing vegetative shoots. It is composed 
of long white hairs from 2 to 4 mm. long. This coma seems to be 
longer and much more abundant than in S. cordata and often is quite 
prominent on young growth. The aments on the only fruiting speci- 
men (Over 14482A of 1923) apparently have been injured by frost 
and are of little diagnostic value. 
The following South Dakota specimens in the herbarium of the 
writer are referred to S. missouriensis. Most if not all of these also 
are in the herbarium of the University of South Dakota at Vermillion, 
and those collected by Ball and Over are being distributed to several 
herbaria. 
Clay Co., Vermillion, Over 13830, Oct. 12, 1922; Grant Co., South- 
shore, Over 15447, July 17, 1923; Day Co., sandy shore of Dry Woods 
Lake, Over 14479, July 5, 1922; Roberts Co., flood plain of Spring 
Creek, Hartford Beach, Big Stone Lake, Over 144824, July 17, 1922, 
May 21, 1923; Ball & Over 2246, Aug. 9, 1923; Hiawatha Beach, 
Big Stone Lake, Ball & Over 2240, Aug. 9, 1923; deep rocky coulee 
5 miles west of Sisseton, Ball & Over 2233, Aug. 8, 1923; shallow coulee 
in prairie 3 miles west of Sisseton, Ball & Over 2235, Aug. 8, 1923. 
In July, 1923, a native willow was found in cultivation on the 
Dickinson Substation, Dickinson, No. Dak., in the west-central part 
of the State. It proved to be S. missouriensis Bebb, but the origin 
of the original cuttings is not known. A similar plant cultivated on 
the Northern Great Plains Field Station, Mandan, No. Dak., probably 
