New species of Uredineae—XV* 
JOSEPH CHARLES ARTHUR 
The following new species and new combinations are the 
result of studies carried on since the publication of the fourteenth 
article in this series, somewhat more than a year ago. They 
include some unusually interesting forms of the Uredinales. 
Coleosporium Spigeliae sp. nov. 
O and I. Pycnia and aecia unknow 
II. Uredinia hypophyllous, in groups 2 2-6 mm. across, on 
slightly discolored areas, the sori o. .3-0.5 mm. apart or somewhat 
confluent, roundish, 0.3—-0.8 mm. in diameter, soon naked, yel- 
lowish or nearly colorless, pulverulent, ruptured epidermis 
inconspicuous; urediniospores irregularly globoid or ellipsoid, 
13-18 by 15-23u,; wall colorless, thin, about 0.54, closely and 
evenly verrucose. 
III. Telia unknown. 
On Spigelia Humboldtiana Cham. & Schlecht. (Loganiaceae), 
Sierra de Apaneca, in the region of Finca Colima, Department 
of Ahuachapan, Salvador, January 17-19, 1922, 20170; near 
Ahuachapan, Salvador, altitude 800-1000 meters, January 9-27, 
1922, 20278 (type); near Quirigua, Department of Izabal, 
Guatemala, altitude 75-225 meters, May 15-31, 1922, 230933; 
all collected by Paul C. Standley 
The sori of this species are pad ant | and have the gross 
appearance of other uredinia in the genus Coleosporium. The 
absence of a peridium and the catenulate, verrucose spores also 
agree with characters of Coleosporium. But all these characters 
could also belong to a species of Melampsoropsis. Moreover, 
the spores are small, the largest scarcely equaling the smallest of 
any other known species of Coleosporium. These consider- 
ations throw some doubt on the present assignment of the 
species. 
Another source of some uncertainty is the presence on the 
same leaves, and often among and close to the uredinial sori, of 
telia-like spores, much resembling a rust. These spores are in 
* Contributions from the Botanical Department of Purdue University 
Agricultural Experiment Station. 
51 
