UREDINALES OF GUATEMALA 
539 
the ostiole; urediniospores ellipsoid, 13-16 by 18-24 /x; wall colorless, 
moderately thick, 1-2 ;u, rather inconspicuously echinulate, the pores 
obscure. 
The forra of the sorus in this species indicates that the rust may 
belong under the genus Pucciniastrum. The flat hymenium, the 
structure of the peridium and its behavior in dehiscence, the pale 
spores with thin wall and obscure pores, are all features strongly 
suggesting Pucciniastrum. The spores, as in species of that genus, 
appear sessile, but fall away as others do that have been found to be 
primitively catenulate. It is probably a species closely related to 
Pucciniastrum pustulatum (Pers.) Diet., and P. Circaeae (Thiim). 
Speg., both of which are on Onagraceous hosts. 
224. Uredo peribuyensis Speg. (on Polygalaceae) . 
Polygala americana Mill., Guatemala City, Jan. 8, 1917, 682. 
This unconnected uredinial form has an applanate sorus, with- 
out paraphyses, and agrees well with the original South American 
collection. The type is published as on Monninia sp., but a collec- 
tion, labeled otherwise as published for the type, is given as on 
Polygala. A third collection, made by C. G. Pringle and communi- 
cated by W. G. Farlow, on P. acicularis, Santa Eulalia Mts., Chi- 
huahua, Mexico, Nov. 15, 1886, can also be placed under this name, 
although the spores are more variable in size than either of the other 
two collections, and have slightly thicker walls. 
225. Uredo Rondeletiae Arth. & Holw. sp. nov. (on Rubiaceae). 
Rondeletia cordata Benth., Guatemala City, Feb. 8, 1917, 842. 
Uredinia hypophyllous, scattered, round, 0.1-0.4 mm. across, 
early naked, pulverulent, cinnamon-brown, ruptured epidermis evi- 
dent; peridium and paraphyses none; urediniospores obovoid-reni- 
form, 13-21 by 23-29^1; wall cinnamon-brown, thin, i ^u, closely 
echinulate, the pores obscure. 
226. Uredo Plucheae Syd. (on Carduaceae). 
Pluchea odorata Cass. 
A collection of this rust was made by Kellerman, at Amatitlan, 
Jan. 25, 1906, 5388, and reported under the synonymous name of 
U. hiocellata Arth. in Journ. Myc. I.e., and thus issued in Kellerm. 
Fungi Sel. Guat. ig. The species is also known from southern Florida 
and from the West Indies. 
