372 



THE FUNGI WHICH CAUSE PLANT DISEASE 



MilMlium 



Leaf Dssue 



17-32 X 14-20 II. II. Urediniospores pale-brown, aculeolate, 24-33 

 X 16-20 II. III. Teliospores elliptical or subglobose, smooth, 



dark-brown, apex much thick- 

 ened, with a small, hyaline, wart- 

 like papilla, 2&-35 x 20-26 ii. 



An autoecious eu-type. On 

 Phaseolus, Dolichos and other 

 related legumes. 



The sori usually appear late 

 in the season on leaves, rarely on 

 stems and pods. The myceliiun 

 is local. Great difference in 

 varietal susceptibility is noted. 



U. pisi (Pers.) de B." 



I. (=^cidium cyparissiae). 



Fig. 267. — Diagramn)atic section of ure- i-, . ij. j j.i i,„i„ 



dinium of U. appendiculatus. After .lEcia scattered over the Whole 

 Whetzel. jgj^f surface. Peridia cup-shaped, 



with whitish edges. Spores subglobose or polygonal, orange, 



finely verrucose, .17-26 /u in diameter. 



II. Uredinia roundish, scattered or crowded, cinnamon-brown. 

 Spores subglobose or 

 elongate, yellowish- 

 brown, echinulate, 17- 

 20 X 20-25 M. 



III. Telia roundish 

 or elliptical, blackish. 

 Spores subglobose or 

 shortly elliptical, finely 

 but closely punctate, 

 apex only slightly 

 thickened, 20-30 x 17- 

 20 n. Pedicels long, 

 colorless, fragile. 



A heteroecious eu- 

 type not found in 

 America: and I on Euphorbia. 



II and III on Lathyrus, Pisum, Vicia. 



The aecial stage dwarfs the host in which it is pereimial 



7. Epidermis 

 ^ "^ of Leaf 



Spores 



— Leaf Tissue 



Young Spore 



Fig. 268 .^Diagrammatic section of teliospores of 

 U. appendiculatus. After Whetzel. 



