UREDINALES OF GUATEMALA 467 
117. Puccinia Aegopogonis Arthur & Holway sp. nov. (on Poaceae and 
Carduaceae). 
Eupatorium Mairetianum DC, Solola, Jan. 25, 1915, O, I, 113. 
Eupatorium sp., Guatemala City, Dec. 23, 1916, O, I, (5jj; same, 
Feb. 14, 1917, O, I, 868\ Huehuetenango, Jan. 21, 1917, O, I, 
754- 
Aegopogon cenchroides Humb. & BonpL, San Rafael, 7000 feet alt.. 
Dept. Guatemala, Jan 9, 1915, II, III, 54 (type); Solola, 7000 
feet alt., Jan. 31, 1915, ii, III, i(54 ; Antigua, Dept. Sacatepequez, 
Dec. 28, 1916, II, III, 650] Huehuetenango, Jan. 21, 1917, III, 
7<5o; Guatemala City, Feb. 14, 191 7, II, 86q. 
Aegopogon tenellus (Cav.) Trin., San Rafael, 7000 feet alt.. Dept. 
Guatemala, Jan. 8, 1915, ii, III, j/. 
Uredinia hypophyllous, scattered, oblong-linear, 0.2-0.5 mm. 
long, cinnamon-brown, pulverulent, early naked, ruptured epidermis 
noticeable; urediniospores globoid or broadly ellipsoid, 21-25 by 23- 
29 /i; wall golden- or light cinnamon-brown, thin, 1-1.5 At, finely and 
closely echinulate, the pores 6-8, scattered. 
Telia hypophyllous, like the uredinia in size and distribution, 
chocolate-brown, early naked; teliospores broadly ellipsoid, 19-24 by 
25-30 rounded above and below, slightly or not constricted at the 
septum, which is often oblique; wall chestnut-brown, moderately thin, 
about 1.5 IX, darker and slightly thicker at apex, 3-5 ^t, smooth; 
pedicel yellowish or colorless, once to twice length of spore. 
The species differs from Uromyc.es Aegopogonis Diet. & Holw. 
(Nigredo Aegopogonis Arth.) by having in general somewhat larger 
urediniospores, and in having two-celled instead of one-celled telio- 
spores. The two forms, or so-called species, are undoubtedly to be 
considered races of one and the same species. 
The same kind of aecia have been found associated with both forms 
in such intimate and unmistakable relation that no hesitation is 
longer felt in connecting them with this species, although no oppor- 
tunity has yet presented itself to confirm the observations by cultures. 
The aeciospores have the somewhat uncommon character of thickened 
wall above, which readily separates them from the aecia of Puccinia 
Eleocharidis Arth. on the same genus of hosts, which have a uniformly 
thickened wall. 
The aecia were described as Aecidium roseum Diet. & Holw., from 
a collection made at Eslava, near the City of Mexico, Oct. 3 or 4, 
1896. The type collection of Uromyces Aegopogonis Diet. & Holw. 
