112 ARTHUR: NEW SPECIES OF UREDINEAE 
The telia of this species have recently been detected by Dr. 
E. B. Mains and prove to be even more distinctive than the ure- 
dinia. They occur in abundance on the Nicaraguan collection and 
sparingly on the one from Guatemala, both specimens having been 
communicated by Mrs. Agnes Chase, who found them in the grass 
collection of the Department of Agriculture. The telia elevate 
the epidermis slightly, but are readily found on account of the 
brown coloration of the surrounding cells. They look, however, 
more like some species of Phyllachora than a Puccinia. The 
teliospores themselves are pale brown and translucent. Owing 
to the firmness of the enveloping tissues and the delicacy of the 
teliospores a scraped mount usually shows only the upper part 
of the teliospores, resembling a parenchymatous mass of tissue. 
Sections are required to reveal the form of the teliospores; they 
show that the central spores of the sorus are usually three-celled, 
while the peripheral spores are often one-celled. Generally the 
two-celled teliospores predominate. 
The type collection and the later one from the same region 
were first reported as on Tripsacum dactyloides, but were later 
found to be on T. lanceolatum. Both collections show the char- 
acteristic small, pale urediniospores, but they also show much 
larger, thick-walled urediniospores of another rust, and in the 
case of one of them a few teliospores also. This association on 
the same leaves led at one time (Bull. Lab. Hist. Univ. Iowa 5: 
174. 1901) to the assumption that only one species was involved 
(P. Tripsaci Diet. & Holw., now referred to P. Ceanothi [E. & K.] 
Arth.), the larger urediniospores being called amphispores. 
The urediniospores on Zea Mays are somewhat larger than 
those on Tripsacum. But as those on the collection of Paspalum 
from Guatemala, having two-inch-wide leaves resembling those 
of maize, are intermediate in size, and as no other grass rust is 
known having such urediniospores, the collection is assumed to 
belong here, awaiting the discovery of telia on this host. The 
size of the urediniospores apparently bears a direct relation to the 
succulency of the host. 
Puccinia imposita nom. nov. 
Uredo Muhlenbergiae Diet.; Atkinson, Bull. Cornell Univ. st .22, 
1897. Not Puccinia Muhlenbergiae Arth. & Holw. 1902. 
