PUCCINIA 297 



Uromyces striatus (Schrot). The aecidium form of this 

 fungus is parasitic on Euphorbia cyparissias, which is dwarfed 

 in a manner similar to that caused by the aecidium condition 

 of Uromyces pisi. The uredospore and teleutospore stages 

 infect various leguminous plants, Trifolium arvense, T. 

 agrarium, T. minus, Lotus corniculatus^ lucerne, etc. The 

 epispore of the teleutospore is marked with fine wavy lines. 



PUCCINIA (PERS.) 



Spermogonia, aecidia and uredospores as in Uromyces ; 

 teleutospores transversely i -septate, each cell having one 

 germ-spore. 



Eupuccinia. Spermogonia, aecidia, uredospores and teleu- 

 tospores produced on the same living host; teleutospores 

 germinating after a period of rest (not on a living host). 



Asparagus rust (Puccinia asparagi, D. C.) not infre- 

 quently destroys the entire crop of asparagus, but in this 

 country fortunately it is sporadic in its appearance. It has 

 proved very destructive in the United States. It often 

 appears somewhat late in the season when the bulk of the 

 crop has been cut, but, on the other hand, the aecidium form 

 sometimes appears on the youngest shoots. This happens 

 when the crop has been infected during the previous year, 

 and diseased material has been allowed to fall and deposit 

 teleutospores on the ground. The uredo-pustules appear 

 later on the stem and branches ; still later in the season the 

 black streaks of the puccinia or teleutospore sori appear, 

 often in such quantity as to blacken the stem and branches. 



Aecidia in lines, margin whitish, torn, spores orange, deli- 

 cately warted, 15-18 /x diam. 



Uredopores brown, echinulate, 20-30 x 17-25 /*. 



Teleutospores elliptical or elongate-clavate, base rounded, 

 slightly constricted, apex rounded, smooth, brown, 35-52 X 

 17-26 /n; pedicel persistent. 



The only possibility of infection in the spring arises from 

 the presence of teleutospores that were produced the previous 

 year, hence it is of primary importance that all diseased plants 

 be gathered and burned before the teleutospores fall to the 

 ground. After the crop is gathered spray the summer stems 

 with Bordeaux mixture, but cleanliness in removing diseased 

 material and cultivating the ground to bury fallen spores are 

 the most certain preventives against a repetition of the disease. 



