1924] Extensions of Range and new Variety in Salix 137 
rocky, timbered coulees or cafions, which contain the headwaters of 
the Minnesota River. 
Through the courtesy of Prof. W. H. Over, of the University of 
South Dakota, the writer was privileged to join a party from that 
institution which was collecting in this district in the summer of 1923. 
Though it was possible to remain for only three days, the trip was 
well repaid. 
The flora of the wooded eastern escarpment of the Sisseton Hills, 
and of the deep rocky coulees that issue from it, is largely an eastern 
flora. Among the plants are the sugar maple, bur oak, American and 
beaked hazelnuts, blue cohosh, and many others. 
The willows of this district are no less interesting than the other 
plants. The abundant occurrence here of S. missouriensis Bebb, 
far to the north of its previously accepted range, is discussed else- 
where in this paper. There seems to be a general tendency toward 
the production of broad-leaved forms. These were collected in the 
glacial trough occupied by Big Stone and Traverse Lakes, and also 
in the coulees of the Sisseton Hills, but not in the plain between. Such 
amplification of the foliar organs was found in four out of seven species 
collected. No specially large-leaved plants of S. interior Rowlee, S. 
cordata Muhl., or S. missouriensis were noted. 
One plant (Ball 2214) of S. amygdaloides And., in a group of several 
plants on the ridge between the lakes, had ovate leaves, a form ' 
collected previously by the writer at Cottonwood, South Dakota, 
west of the Missouri River. One plant of S. lutea Nutt. (Ball & 
Over 2232), out of several seen in a coulee in the Sisseton Hills, had 
ovate leaves very suggestive of S. lutea platyphylla Ball from the 
Wahsatch and Great Basin sections. Of S. bebbiana Sarg., only a 
single plant was seen, in a coulee, but it (Ball & Over 2230) has rather 
large obovate-oval leaves, quite different in shape from those of the 
normal plant of this species. Finally, a very broad-leaved form of 
discolor is here described as a new variety. 
SALIX DISCOLOR overi Ball n. var. Tree up to 8 inches in diameter 
and 15-20 feet tall; branchlets short and divaricate, the bark dark 
brown, reddish brown or sometimes yellowish, not shining, glabrous 
or the most recent growth slightly puberulent, usually wrinkled 
longitudinally; stipules none or, on sprouts, 2-7 mm. long, subreniform 
to semicordate, acute denticulate, often deciduous; leaves broadly 
elliptical to oval or broadly obovate, on flowering or fruiting branches 
mostly obovate, subremot ely and coarsely or shallowly crenate-serrate 
