196 Bulletin 313 



surface of a leaf, cupulate, short, 0.2-0.4 mm. in diameter ; peridium 

 whitish, the margin spreading or somewhat recurved, irregularly 

 lacerate; peridial cells rhomboidal, 12-16 by 16-24 /*, the outer wall 

 rather thick, 6-7 fi, striate, the inner wall thinner, 3-4 /a, moderately 

 verrucose; aeciospores globoid, 12-16 by 14-18 [x.; wall colorless, thin, 

 1-1.5 fx,, finely verrucose." 



"II. Uredinia amphigenous, scattered, roundish, about 0.4-0.7 

 mm. across, rather early naked, pulverulent, dark cinnamon-brown, 

 ruptured epidermis noticeable ; urediniospores broadly ellipsoid or 

 obovoid, 15-23 by 20-26 fx, wall golden-brown, 1.5-2 /x thick, finely 

 and rather sparsely echinulate, the pores 2 or 3, approximately 

 equatorial." 



"III. Telia amphigenous, scattered, roundish or oval, 0.5-1 mm. 

 or more across, rather early naked, somewhat pulverulent, slightly 

 pulvinate, chocolate-brown, ruptured epidermis conspicuous ; telio- 

 spores obovate or oblong, 15-23 by 22-35 ix, roundish, obtuse, or less 

 often acute above, usually narrowed below ; wall light to dark cinna- 

 mon-brown, moderately thick, 2-2.5 /a, much thicker at the apex, 

 5-10 [X, smooth pedicel somewhat tinted next to the spore, fragile, 

 about one and a half times length of spore, usually broken away and 

 appearing short." North American Flora, v. 7, p. 262 (1912). 



1036. Uredospores, 1/12. 



NiGREDO POLYGONi (Pers.) Arthr. — On Polygonum sp. 



"O. Pycnia amphigenous, few, in small groups, about 0.5 mm. 

 across, inconspicuous, honey-yellow becoming brownish, depressed- 

 globoid, 112-144 fx in diameter, 75-100 ^x high, ostiolar filam.ents 75- 

 90 IX long." 



"I. Aecia amphigenous, gregarious, in annularly or crowded 

 groups 1-1.5 mm. across, on discolored spots, short, cupulate, or oc- 

 casionally somewhat elongate, 0.1-0.2 mm. in diameter; peridium 

 colorless, the margin cross ; peridial cells rhomboidal 26-32 /a long, 

 overlapping, the outer wall rather thick, 6-8 fx, transversely striate, 

 the inner wall thinner, 2-3 /x, somewhat striate, very moderately ver- 

 rucose; seciospores globoid, 15-18 by 16-19 (x; wall light yellow or 

 colorless, thin, 1 [x, finely verrucose." 



"II. Uredinia amphigenous, scattered, roundish, 0.3-0.8 mm. 

 across, early naked, somewhat pulverulent, cinnamon-brown, rup- 

 tured epidermis conspicuous ; urediniospores broadly ellipsoid or 

 obovoid, 15-22 by 19-27 /*; wall golden-brown 1.5-2 fi thick, finely 

 and closely verrucose, the pores 4, equatorial.'' 



