200 Bulletin 313 



brown, ruptured epidermis conspicuous ; urediniolspoTes broadly 

 ellipsoid, 18-21 by 21-26 /x, wall golden-brown, rather thin, about 1.5 

 /m, rather sparsely echinulate, the pores 3 or 4, equatorial." 



"III. Telia chiefly hypophyllous, scattered, oval or roundish, 

 variable in size, 0.3-0.8 mm. or more in diameter, rather tardily 

 naked, somewhat pulverulent, chestnut-brown, ruptured epidermis 

 conspicuous; teliospores broadly ellipsoid or obvate-ellipsoid, 13-19 

 by 20-29 /jl; wall cinnamon-brown, rather thin, about 1.5 /x, with a 

 small hyaline papilla O'ver the germ-pore, smooth, or with a few, 

 small sparsely scattered papilla; ; pedicel colorless or slightly tinted, 

 short." North American Flora, v. 7, p. 255 (1912). 



1041. Infected leai; of Trifolium repens. 1042. Peridial cell, 1/12. 1043. 

 Aeciospore, 1/12. 1044. Uredospore, 1/-2. 



NiGREDO PRCEMiNENS (D. C.) Arthur.- — On Euphorbia preslii, de- 

 scribed by Arthur (manuscript) as follows: 



Pycnia hypophyllous, widely scattered among the secia, rather 

 few, punctiform, honey-yellow becoming brownish, globoid, 130-145 

 fi in diameter ; ostiolar filaments up to 65 /x long. 



Aecia chiefly hypophyllous, from an unlimited mycelium, usually 

 occupying all of the under surface of the afi^ected leaves, evenly and 

 often densely scattered ; short, cupulate, 0.3-0.4 mm. in diameter ; 

 peridium somewhat recurved, lacerate; peridial cells rhomboidal, 

 somewhat overlapping, 13-19 fi broad by 18-25 /x long, the outer 

 wall ratlier thick, 4-7 fx, transversely striate, smooth, the inner wall 

 thinner, about 3 fx, somewhat striate, somewhat verrucose ; aecio- 

 spores globoid or broadly ellipsoid, 12-16 by 15-19 fx, wall pale yel- 

 low or colorless, thin, 1 /*, finely and densely verrucose. 



Uredinia amphigenous, scattered or sometimes in annular or 

 crowded groups, roundish, 0.4-1 mm. across, early naked, pulvinate, 

 pulverulent, cinnamon-brown, ruptured epidermis not conspicuous ; 

 urediniospores globoid or broadly ellipsoid, 15-20 by 19-23 [x; wall 

 pale golden brown, rather thin, about 1.5-2 /x, moderately and 

 sparsely echinulate, the pores 3-6, scattered. 



Telia amphigenous, scattered or sometimes in annular groups, 

 roundish, 0.4-1 mm. across, early naked, pulvinate, somewhat pul- 

 verulent, dark chocolate-brown, ruptured epidermis not conspicu- 

 ous; teliospores broadly ellipsoid or obovoid, 15-18 by 18-26 /x, usu- 

 ally rounded at both ends ; wall cinnamon-brown, rather thin, 1 .5 /x, 

 with a lighter-colored, flattish or conical papilla over the germ-pore, 

 moderately vc. rucose with papillae scattered or sometimes arranged 



