A contribution to a revision of the North American Hydnaceae 
HOWARD JAMES BANKER 
The following paper is intended to include a revision of all the 
pileate forms of the family of the Hydnaceae which have been 
found on the continent of North America and its adjacent islands 
north of the Isthmus of Panama. А few resupinate forms have 
been included by reason of their close relationship to pileate 
forms, but in general they have been excluded. The reason for 
this arbitrary limitation of the scope of the work is the impossi- 
bility of adequately treating the resupinate forms and referring 
them to their proper species until such time as the Berkeley types 
can be thoroughly examined by one familiar with our American 
plants. 
The Hydnaceae represent one of the smaller families of the 
Basidiomycetes, there being not more than five hundred known 
species in the family, and of these not more than two hundred 
have been reported within the geographical limits of this paper: 
With a few exceptions the species are not common and gener- 
ally appear to be quite local in distribution. The task, there- 
fore, of getting suitable material on which to base a revision of the 
family has proved more difficult than was at first anticipated. Nor 
are the herbaria of collectors as helpful as one would have a right 
to expect. The published descriptions of species of this family are 
frequently incomplete and inadequate to fully discriminate the spe- 
cies, so that it is possible often to include several different species 
under the one description. Collectors are inclined to refer speci- 
mens according to some conspicuous feature, such as a scaly 
pileus or a zonate pileus, and then pay little attention to other ap- 
parently minor characters. Owing to the local character of the 
distribution of these plants, combined with the comparative rarity 
with which they are found, few discover that the plants which they 
are referring to a given species are very different from the plants 
Memoirs Torrey Botanical Club, Volume 12. 
(Хо. 2 issued 13 June, 1906. ] 
