99 
versa, they should be placed together. I mention these cases to show 
how destructive some fungus diseases are some years and they do not 
appear at others. 
Clover Rust , (Uromyces trifolii , Alb. & Schw.) Wint., is referred to by 
Prof. Dudley in a recent bulletin as occurring on red clover in New 
York in a very destructive Avay. I think it has not been previously 
reported on that host in this country, though occurring abundantly on 
it in Europe, according to Frank, Kraft, and others. Clover rust has 
long been known to occur ou white clover in this country, and is at 
times quite destructive. In August my attention was called to the 
rust occurring on the campus close to the botanical laboratory. The 
plants affected were somewhat trodden, but nearly every stalk had its 
leaves badly diseased. The affected plants soon withered. After the 
first discovery the rust was soon noticed some 30 feet away, attacking 
the leaves and stems. It was quite general, as students brought speci¬ 
mens in from the field and various places on the college farm and 
campus. During the months of August, September, and early October, 
only uredospores were found, but later teleutospores were produced 
very abundantly. The stems were marked with longitudinal brownish 
sori so thick that in touching the plant the hands were colored brown. 
The teleutospores made their appearance first ou the stems, and later 
they appeared on the petioles and leaves. 
TJromyces trifolii also occurs on crimson clover ( Trifolium incarna- 
tum)* Some years ago it was very bad in an experimental plat at 
Madison, Wis. The fungus is more destructive to this plant than to 
red clover. It lias also been found on the same host at Ames by Mr. 
Sirrine. In this country the fungus has been principally reported as 
destructive on white clover, and commonly all three stages occur on it. 
Miss Howell has recently shown that the fungus on red and on Avliite 
clover is identical, and that the uredo and teleutospores can be produced 
from the secidium which appears early in the summer. 
II.— FRUITS AND FRUIT TREES. 
Plum Scab or Black Spot. —For two seasons I have Avatched with some 
interest a fungus which causes the plums of some of the cultivated 
varieties of Prunus Americana , especially the Miner, to become spotted 
and more or less scabby. So far as I know this has not been recorded 
before, though Professor Osborn informs me lie has observed a similar 
appearance for some years. It is not improbable that the disease may 
be quite common in the Northwest. The cause of the spotting is a par¬ 
asitic fungus Avhich seems to be closely related to the fungus causing 
the black spot disease of peaches ( Cladosporium carpophilum.) The 
last species Avas described by Felix Yon Tlminen in 1887 f and he records 
* Treleaso Parasitic Fungi of Wisconsin, No. 152, p. 21. 
t Syrnb. Mycol., p. 107. 
