Botany. 1117 
_ A second tumble-weed is Cycloloma platyphyllum Moq. It grows 
in almost exactly the same way as the preceding. I first observed 
it along the Platte River, where it covered acre after acre of the 
sandy river border. It occurs also on the upper Elkhorn River 
and the lower and middle portion of the Niobrara. owever, 
upon the upper Niobrara and in the White River country the only 
tumble-weed is Amarantus albus. Probably this second plant 
(Cycloloma) has for a long time been a tumble-weed upon the plains, 
especially on those portions adjacent to the streams mentioned. 
Both species will increase in numbers for a few years, during the 
time when settlers are breaking up large tracts of the prairie sod, 
and then, as better and more continuous culture is practiced, they 
will gradually decrease in number and importance.—Charles E. 
Bessey. 
Asn Rust IN 1888.—The Ash-rust, Zcidium frazini, has been 
very abundant on Frawinus viridis in Lincoln, Neb., this year. It 
was especially common in the latter part of June and first week of 
July. At that time I observed a number of trees of which almost 
every leaf (as also in many cases were the petioles) was affected to 
such a degree that many of them were curled and distorted. This 
some interest from the fact that, although abundant in 1885, 
this rust was rare in 1886 and 1887.—N. R. Pound. 
orty pages are devoted to a systematic study of the species repre- 
sented in the sections. Under each species there is first a specific 
description of the tree given in quite popular language; then fol- 
low geographical distribution, physical properties, uses, medic 
properties, ete. Accompanying this part are three keys to the spe- 
cies: the first based mainly upon the flowers, the second upon the 
