UREDINALES OF GUATEMALA BASED ON 
COLLECTIONS BY E. W. D. HOLWAY 
IL Aecidiaceae, Exclusive of Puccinia and Form-Genera 
J. C. Arthur 
The first portion of this account of the Guatemalan rust flora was 
issued in a previous number of this journal (June, 1918, pp. 325-336), 
and listed the twenty-two known species belonging to the families 
Coleosporiaceae and Uredinaceae. For convenience in indexing, the 
species are numbered consecutively with the previous part. The 
portion here submitted and the parts to follow will deal with the family 
Aecidiaceae (Pucciniaceae). The genera Pucciniosira, Endophyllum, 
and the very similar Endophylloides, are usually placed with the 
Uredinaceae (Melampsoraceae), but it is believed that their affinities 
are better expressed in the present connection. 
There are 79 species listed in this second portion, which fall into 
sixteen genera, all being small with one to three species each, except 
Ravenelia and Uromyces with twenty and thirty-five species respec- 
tively. The genus Ravenelia has its greatest development in the 
tropics, and the addition of five new species at this time indicates that 
many more new forms are yet awaiting discovery. 
Probably the most interesting and striking new species of the eleven 
that are included in the paper is the one which introduces the genus 
Skierka to the flora of the western hemisphere. The whole mor- 
phological structure is unusual, and the long, flexuous filaments of 
agglutinated urediniospores, after the fashion of Uredinopsis, give to 
the specimen an astonishingly close resemblance, when seen with the 
naked eye or a hand lens, to the telia of Cronartium. 
The species next in interest is Dicheirinia binata, for although the 
name was published sixty years ago the identity of the host has re- 
mained wholly conjectural until now, not even the family having been 
correctly suspected. It was originally collected in Nicaragua, a 
country adjacent to Guatemala. Recent collections were passing 
under the name Uredo Cabreriana. 
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