UREDINACEAE 409 



Cronartium flaccidum, Winter, Krypt. -Flora, i. p. 236. 

 Uredospore sori forming pustules, minute, ochraceous, 

 or pale brown, pseudoperidium very firm, plano-convex; 

 uredospores roundish, ovate, piriform, etc., i8-44X 12-20 /*, 

 aculeate, pale orange; teleutospores forming a cylindric- 

 oblong, often curved or tortuous column 2 mm. high, pale 

 brown, teleutospores oblong or cylindrical, ends obtuse, 

 brown, 8-12 p. diam. 



Aecidium condition unknown. 



Melampsora, Cast. Spermogonia forming minute, orbi- 

 cular, covered patches ; aecidia (Caeoma form), destitute 

 of a pseudoperidium ; spores in chains ; uredospores pro- 

 duced singly at the tips of sterigmata, aculeolate, enclosed 

 in a more or less developed pseudoperidium ; teleutospores 

 i -celled, obovate-cuneate, compacted into a firm, crustlike, 

 plane stratum ; sporidiola subglobose, yellow, or orange. 



Melampsora pinitorqua, Rost. = J/. populina, LeV. 

 Caeoma stage, sori mostly linear, up to 2 cm. long, solitary 

 or crowded, orange, spores round or polygonal, 15-20 n, 

 warted, pale rufous yellow ; uredospore sori rounded, often 

 bullate and confluent, orange-rufous, spores elliptic or 

 ovoid, 28-38 X 13-20 ju, aculeate, orange; paraphyses more 

 or less abundant, up to 50 n long, swollen apex 17-20 /* 

 broad ; teleutospore sori epiphyllous, flattened, often 

 confluent, at first rufous-brown, then blackish-brown, 

 teleutospores 40-45 x 13 /*; sporidiola globose, orange. 



Melampsora laricis, Rost, Caeoma /aria's, Hartig. 

 Melampsora tremula caeoma stage, sori narrow, 500 p. to 

 5 mm. long, on a yellow spot ; spores round or elliptical, 

 16-24X12-17 /*, delicately warted, orange-yellow; uredo- 

 spore sori often expanded on twigs, rufous orange, rounded 



