rors] _BALL—WILLOWS 5I 
The types of NUTTALL’s numerous species in § LONGIFOLIAE have re- 
cently been studied by Professor C. V. Piper at the British Museum. As a 
result of this examination it appears, among other things, that the type of 
Salix sessilifolia is quite different from the plant usually described under that 
name by American authors. . From the illustration (fig. 2) and from the full 
redescriptions prepared, the identity of S. sessilifolia should be established 
readily. It is seen to be a plant with the leaves on the fruiting branches small, 
truly lanceolate, and actually sessile! The leaves and the twigs of the season 
are densely clad with a pilose tomentum of gray hairs which are spreading on 
the petiole and midrib and more or less appressed on the blade. The capsule 
also is densely pilose, even in age. True S. sessilifolia belongs, therefore, in 
the group containing S. argophylla and S. macrostachya (as these are at present 
understood) rather than with the S. fluviatilis-melanopsis aggregation. Just 
what are the limits of variation in S. sessilifolia, as well as the more certain 
identification of the relatives named above, cannot be settled at this moment. 
Further study of Nutrat’s types and of collections from the type localities 
will be necessary to a final decision. The plant commonly identified and 
described as S. sessilifolia is here treated provisionally as S. fluviatilis Nuttall. 
SPECIMENS EXAMINED.—OREGON: Elihu Hall 474, in 1871 (FBb 6271, Gray 
[fig. 2] distributed as S. desertorum Richardson; the Gray Herbarium neat 
with “desertorum”’ elided and “S. sosstlifella var. villosa” written in; the 
specimen in the Bebb Herbarium identified by BEBB as S. sessilifolia var. 
villosa; both specimens attested as S. macrostachya Nuttall by RowLee); 
Cusick (said by Rowtexr to be no. 1514), said by Cusick (fide Prrer) to have 
been collected in Linn County, Oregon, probably on the Willamette River 
(FBb 994). 
CaLiForNiA: In most of the Californian specimens having leaves densely 
villous-tomentose with somewhat spreading gray hairs, instead of villous with 
appressed silvery hairs, the leaves are much narrower than in the typical S. 
sessilifolia. Such material is found under the names S. sessilifolia, S. argo- 
phylla, and S. hindsiana. Two Californian specimens which rather closely 
approximate true S. sessilifolia in habit and in shape, size, and vesture of the 
leaves are cited below. Their leaves, however, are not so distinctly lanceolate, 
nor are they spinulose-denticulate so far as observed, but they do possess 
small stipules. Marin County, W. H. Brewer 2360, in 1863 (FBb 6172) or 
1866 (G); Nasismento R., W. H. Brewer 544, May 3, 1860-1862 (G, on same 
Sheet with the preceding). 
J. G. Jack’s plant from Grant’s Pass, Oregon, Aug. 23, 1904 (G) may 
represent the glabrate autumnal aspect of the species. The leaves, though 
broad, are blunter and quite entire. The spinulose teeth may be deciduous, 
however. Cusick’s 4407 from Roseburg, Oregon, 1914 (B) is the same as Jack’s 
plant, but with densely pilose-tomentose, stipulate, sharply apiculate leaves 
which are spinulose-denticulate. His no. 4457 differs only in the more linear 
leaves; both bear foliage only. 
