326 BOTANICAL GAZETTE [OCTOBER 
separate them.”’ He adds that he is not “able to find in the descrip- 
tion [of Seemannii] a record of any characters that serve to dis- 
tinguish the specimens assigned to the latter species from forms of 
glauca found in America and Europe.” I agree with CovILLE that 
the North American forms are very similar to those of S. glauca, 
but they are in my opinion not fully identical with the typical 
S. glauca L. s. str., the characters of which I have already indicated. 
In looking over the copious and well collected American specimens 
before me, I hesitate to designate them as typical S. glauca, nor 
am I willing to regard them as a separate species until a closer study 
of this circumpolar willow has convinced me of one fact or the other. 
Those specimens exhibit a great degree of variability in the shape 
and size of the leaves, in the amount of pubescence, in the length 
of the aments, and in the characters of the flowers. As a whole 
they seem to differ from the typical .S. glauca by the usually well 
developed stipules, by the longer pedicels of the fruits which nor- 
mally are from one-half to twice longer than the gland, and by the 
tendency of the filaments to become almost glabrous. Judging by 
Covittr’s statement with regard to S. reticulata, that “in all the 
other Alaskan willows the filaments are glabrous throughout,” I 
supposed that this fact might furnish a good character to separate 
specifically the American S. glauca from the European-Asiatic 
species, but a close investigation of all the male specimens at my . 
disposal convinced me that the filaments are always more or less 
hairy at their base. Specimens like nos. 3369 or 3373 of TRELEASE 
~ and SAUNDERS, which apparently have entirely glabrous filaments, 
do not seem to be pure S. glauca, and the American form probably 
hybridizes with other willows as freely as does the European one. 
If we regard the American S. glauca as a distinct variety, we 
have unfortunately to use the varietal name acutifolia given by 
Hooker to his variety of S. villosa, because it antedates ANDERS- 
son’s S. glauca villosa by almost 30 years, and apparently represents 
a rather extreme form with narrowly lanceolate leaves. I regar 
my determinations as rather provisional, and I am not convinced 
that my present limitation of the Northeastern American forms 
of S. glauca can be taken as a definite solution of this difficult 
question. 
