218 lUhurls State Ldhorntnri/ of Natural Histonj. 



Schweiiiitz, and as such (listri))ute(l by Raveiiel in his Fungi 

 Carolmiani IV. No. 99, and Fungi Americani, No. 488. In 

 both of those specimens the Coleosporium form is found. Our 

 specimens on Ipomdea Nil have the spore-chains somewhat more 

 slender, and the color of those examined is not quite so deep as 

 tliat of those on I. pandurata. 



Chrysomyxa, ITngee. 



Teleutospores composed of several cylindrical cells in sim- 

 ple or branched vertical rows, the lower cells sterile, each of 

 the upper producing a several-celled promyceliura bearing about 

 four sporidia, sorus naked, compact, flat or convex, red or 

 orange-yellow: uredospores in vertical rows, soon pulverulent, 

 sorus naked. 



It is understood that Pcridennluni ahietiniiin. ( Alb.& Schw.) 

 is genetically related to one or more species of this genus as 

 the iecidium-stage. 



Not so far observed in Illinois. 



Uredo, Lev. 



Spores one-celled, produced singly on pedicels from which 

 they readily separate at maturity, forming a powdery mass; 

 sorus without pseudoperidium, without spermagonia. 



Many, perhaps all, are forms of plants belonging to other 

 genera classified by the teleutospores, as UroDiijces, Pucc'tnia, 

 etc., and constitute what is known as the second stage of the 

 Uredinea'; but some of the so-called species have not yet been 

 connected even in supposition with any teleutosporic forms. 

 The spores germinate at maturity, and soon lose their vitality; 

 the germ tube produces the mycelium directly, without the in- 

 tervention of sporidia. The sorus is in some cases surrounded 

 l)y paraphyses, usually club-shaped and incurved, a character- 

 tic of the so-called genus Lecythea. 



For the comparison between Uredo and Caviua^ see the 

 latter. 



