ReEPoRT OF THE BoTANIST. LH 
That these parasites are injurious to the plants they attack is 
manifest, since they diminish their vigor and thus impair both the 
quantity and quality of the seed. It is this fact that makes “rust ” 
and ‘‘ mildew ;’’ words of such terrible import to the farmer. He 
dreads the advent into his grain fields of the pest they indicate, and 
the tearful injury it is capable of inflicting upon his pecuniary interests. 
The condition of these plants known as “rust” or Trichobasis 
generally precedes the true Puccinia development. In this state the 
spores are of a reddish-yellow or rust color, subglobose in form and 
simple. They have no septum, and when fully mature no peduncle. 
But sometimes the two kinds of spores may be found intermingled 
in the same sorus. 
In the following synopsis an attempt has been made to group the 
species according to their aftinities and to give the characters so fully 
that the student may satisfactorily identify the species. The color 
of the spot is given as it appears on the upper surface of the leaf, or 
on that surface which is opposite the spore clusters. The measure- 
ments are of moistened spores and are given in decimak of an inch. 
They may in some cases be a little too large for dry spores. Figures 
of the spores have been drawn by the aid of the camera lucida, they 
being uniformly magnified four hundred diameters. Although the 
spores in the same species and even in the same cluster vary within 
certain limits, they doubtless furnish the most reliable characters for 
the discrimination of the species. In selecting spores for illustration, 
those were chosen which seemed to represent the prevailing form or 
forms in each species. 
§ 1. Spores elliptical, obtuse, not at all or but slightly constricted ; 
peduncle very short, hyaline. 
1. P. puntcnetta Peck. Currant Brand. 
Spots yellow or greenish-yellow, orbicular, rarely confluent ; 
sori sinall, circinating, sometimes confluent, blackish-brown ; spores 
.001—.0013' long, .0006’ broad. 
Upper surface of leaves of Ribes prostratum. North Elba, 
Essex county. July. 
This species is as rare as it is beautiful, having been found in no 
other locality than the one reported. It is remarkable, from the 
fact that the sori occur only on the upper surface of the leaf. 
These are usually arranged in two circles, one within the other, 
and both surrounding a central sorus or cluster of confluent sori. 
The spots are about one-eightl: of an inch in diameter and nearly 
equal, 
2. P. mesomasatis B. & C. Clintonia Brand. 
Spots orbicular or elliptical, dull yellowish or brown, sometimes 
with a darker margin ; sori minute, surrounded by the ruptured 
remains of the epidermis, clustered, frequently crowded, cinnamon- 
. 
