June, 1901] 
Griggs — Vernation of Salix 
125 
this backward turning is merely a character of the mature leaf 
manifesting itself in the bud it is evident that there is here no re- 
volute vernation but that it is really imbricate. 
The other buds examined vary from the form represented in 
figure 1 where the whole interior of the bud is taken up with the 
closely packed leaves, to that shown in figure 2 where there are a 
few leaves with a great deal of wool. 
Species like Salix fragilis L. whose leaves are glabrous when 
they unfold have buds like the former while species like Salix dis- 
color Muhl., with leaves excessively wooly when they unfold, are 
like the latter. As there are all intergradations between these two 
kinds of leaves, there is naturally a series of buds between these two 
as extremes. While further investigation is necessary before we 
would be warranted in declaring that the vernation of the whole 
genus is imbricate ; yet the fact that specimens of thirty-four species 
and varieties, taken from thirteen of the nineteen sections given by 
Andersson in DeCandolle’s prodromus, have their leaves imbricated 
in the buds would seem to establish a presumption in favor of such 
a view. 
The buds examined were soaked in 70 % alcohol and free-hand 
sections cut and mounted in balsam. On account of scarcity of 
material, the buds of several species were not sectioned but dissected 
on the growing plant. Such are marked with an asterisk (*). As 
far as possible living material was taken, mostly from native plants. 
Those species not native were studied from specimens growing in 
