406 PLANT DISEASES 



UREDINACEAE 



Mycelium developed in the tissues of living plants. 

 Spores produced at the tips of hyphae, usually of more 

 than one kind, as spermogonia, aecidia, uredospores, 

 teleutospores; the latter on germination form a pro- 

 mycelium, which is typically 4-septate, each cell producing 

 a conidium borne on a slender sterigma. 



Uromyces, Link. Spermogonia present in many species; 

 aecidia having the pseudoperidia usually well developed ; 

 sori of uredospores flat, small ; sori of teleutospores more 

 or less pulverulent, flattened or pulvinate, teleutospores 

 i-celled, with a single apical germ-pore, stipitate; second- 

 ary spores subhyaline, ovoid or elliptical. 



Uromyces appendiculatus, Link., Obs., ii. p. 28. Sper- 

 mogonia on white spots; aecidia on spots 1-2 mm. broad, 

 shortly cylindrical, margin deeply cut, whitish, aecidio- 

 spores angularly globose, 17-32X14-20, hyaline, slightly 

 punctulate ; uredospores in small pale brown sori, 24-33 x 

 16-20, pale brown, aculeolate ; teleutospores forming small 

 blackish sori, elliptical or subglobose, smooth, dark brown, 

 apex much thickened, and with a small, hyaline, wartlike 

 papilla, 26-35 * 20-26 /A. 



All forms produced on same leaf. 



Uromyces colchici, Massee, Grev., xxi. p. 6. Sori 

 numerous, large, elliptical, sometimes circinating, blackish- 

 brown, on both surfaces of leaf arid on leaf-sheath; 

 teleutospores broadly elliptical or subglobose apex, slightly 

 prominent, germinating pore i ; epispore dark brown, 

 smooth, up to 2 ft thick, 28-38x21-28 /*, pedicel hyaline, 

 persistent, base attenuated, 70-80x5-6 /*. 



