400 
Notes on the Pine-inhabiting Species of Peridermium. * 
By Lucigen M. UNDERWOOD AND F, S. EARLE. 
There seems to have been much confusion regarding the pine- 
inhabiting species of Peridermium not only in this country but also 
in Europe, and the difficulties in the way of a clear understanding 
of the species have not been entirely removed. So far as we have 
been able to discover we have only three species of this group in 
the eastern United States besides three nominal species from 
western North America which we have not been able to eX 
amine.t It is possible that the examination of the type of an- 
other Eastern species (now inaccessible for the time) may reveal 
some features that its description does not show and require fur- 
ther modification of the synonymy. 
Two of our species are foliicolous and produce only a minimum 
of disturbance in the tissues of their host, while the third is found 
only on stems producing extensive gall-like swellings often of 
enormous size. These may appear on the smaller limbs, or 0? 
_ branches of various sizes, or on the main trunk of trees of com 
siderable diameter. So far as the economic relations are com 
cerned, the foliicolous species rarely produce any considerable 
damage, but the stem-inhabiting species causes extensive damage 
in some portions of the South in the deterioration or death of | 
chiefly young pines. The Eastern species are as follows: 
1. PERIDERMIUM ACICOLUM (Wallr.). 
P. pint var. acicolum Wallr. Fl. Crypt. 262. 1833. 
P. oblongisporium Fuck. Symb. Mycol, 42. 1869. 
This species, which is very distinct from the stem-inhabiting 
Peridermium pini of Europe, appears to be confined to the North- 
eastern states and is not separable from the forms occurring in Eu- 
rope on various hosts. With us it has been found only on Pius 
vigida, We have seen specimens from Massachusetts (Underwood, 
Seymour) and New Jersey (Pennypacker) only. The spores af 
" * Read before Section G, A, A, A.S,, Buffalo meeting, August, 1896. 
+ #. Englemanni Thuem., from Colorado; P._filamentosum Peck, from At ; 
and PF. Harknessii Moore, from California. 
