1902] THE UREDINE.^ IN AMERICA I? 



This cosmopolitan species shows no American peculiarities 



{fiS'4y^^^y a^d u^ except the great rarity of the aecidial form. 

 The teleutospores, however, are strongly viable, and grow 

 readily on Rumex crisptts and R. ob tusifo litis , forming normal 

 aecidia exactly like those collected in the open in Europe/** 

 The aecidia, which are small, colorless, and inconspicuous, have 

 so far only been found once with certainty in America. 



The reasons for selecting the name here adopted should 

 probably be stated. There is no question but that Persoon's 

 Vadium ritbellum included the aecidial form of this species of 

 Puccinia, and that it is the oldest name. His diagnosis ran as 

 follows : ** Ae, ricbnun. a rumicis, thecis coiigestis seminibiisque 

 albis. /9 grossularicE, thecis sparcis seminibiisque pallidis.'' The 

 name might evidently have been written P, Rumicis, had that 

 name not already been applied elsewhere. In writing P. rubella 

 it is assumed that, w^hen all the forms composing a species are 

 serially separated, as indicated by letters or otherwise, the spe- 

 cific name covers the first of these varieties, whether this first 

 variety is given a distinctive name or not. If in such a case the 

 varieties are erected into species, the first one may bear either 

 the specific or the first varietal name. 



6. Puccinia simillima, sp. nov. 



Exsicc: Sydow, Ured., 274"^ in part. 



O. I. Spermogonia and aecidia uncertain. 



II. III. Sori amphigenous, low and rather small, oblong, 

 elongated on sheaths, ruptured epidermis somewhat noticeable. 

 11. Uredosori light yellow, pulverulent, with clavate paraphyses ; 

 uredospores obovate or oblong-clavate, 18-22 by 26-44 Z^, wall 

 of medium thickness, golden yellow, minutely tuberculate and 

 sometimes slightly echinulate, pores indistinct, scattered, 

 number undetermined. III. Teleutosori small, very numerous, 

 nearly or quite black ; teleutospores at first arising from the 

 uredosori, linear-oblong or oblong-lanceolate, very little con- 

 stricted at the septum, 15-20 by 42-56 /x, base narrowed, side 

 walls thin, apex acuminate, acute or less often obtuse, thick- 



10 



Arthur, Box. Gaz. i8: 269-270. Ap 1900. 



