468 
J. C. ARTHUR 
was also taken near the City of Mexico, Oct. i, 1896. A collection of 
aecia was made at Amecameca, near the City of Mexico, on Oct. 20, 
1903, and of telia Oct. 22, 1903. Collections of both aecia and telia 
were made at Patzcuaro, Oct. 19, 1898. Many other collections were 
made of both stages in these and nearby localities as well as elsewhere in 
central Mexico. 
It was not, however, until Prof. Holway was collecting in Guate- 
mala in January, 191 7, that the genetic connection of the two stages 
was clearly suspected. On Jan. 21, of this year, at Heuhuetenango, a 
clump of some shrubby Eupatorium was found completely covered 
with Aecidium foseiim (no. 754). It w^as at the bottom of a high bank, 
with Aegopogon cenchroides on the bank above, well rusted with Piicci- 
nia Aegopogonis (no. 760), and no other sedge or grass rust in the 
vicinity. The same close and well isolated association was again 
found on Feb. 14, 191 7, near Guatemala City (nos. 868 and 869). 
The circumstantial evidence is both direct and abundant, indicating 
that the apically thickened aeciospores on Eupatorium go genetically 
to the Aegopogon rust, and that they are not part of the rust on Eupa- 
torium, which since 1906 has often been called Puccinia rosea, but 
should go under the name P. Conoclinii Seym. The name Aecidium 
roseum Diet. & Holw., should technically be entered as a synon3^m 
under Uromyces Aegopogonis. 
The rust was collected by Kellerman, on phanerogamic specimens 
now in the National Herbarium, of A. cenchroides, Santa Maria, Dept. 
Quezaltenango, Feb. 5, 1905, II, 5572, and Cerro Quemada, Dept. 
Quezaltenango, Feb. 8, 1906, III, 5932, 5948. 
118. Puccinia subdigitata Arthur & Holway sp. nov. (on Poaceae). 
B r achy podium mexicanum (Roem. &Schult.) Link, San Rafael, 7000 
feet alt., Dept. Guatemala, Jan. 7, 1915, II, III, 2j. 
Uredinia amphigenous, scattered, elliptic, small, about 0.5 mm. 
long, early naked, yellowish, pulverulent, ruptured epidermis incon- 
spicuous; paraphyses few, oblong or clavate, 10-15 by 26-35 f^i the 
wall pale cinnamon-brown, 1-2 /j, thick; urediniospores globoid or 
broadly ellipsoid, 12-15 by 14-19 m; wall thin, i ju or less, pale yellow 
or colorless, finely and closely echinulate, the pores obscure, probably 
scattered. 
Telia chiefly hypophyllous, crowded but seldom confluent, elliptic 
or oblong, 0.5-1 mm. in length, dark gray, long covered by the epider- 
mis bordered by a thin layer of dark brown stromal hyphae; telio- 
spores oblong or clavate-oblong, 10-16 by 27-45 fx, the apex truncate, 
