UREDO 335 



Aecidia cylindrical, white, on yellowish spots in one or 

 two rows on the leaves ; spores orange-yellow. 



Uredospores subglobose, orange, warted, 17-28 X 15-22 /x. 



Teleutospores 10-14 l x broad, not widened upwards, ob- 

 tusely rounded. 



Not a very injurious parasite. The removal of either of 

 the hosts from the vicinity of each other checks the 

 disease. 



De Bary, Bot. Ztg., 1879. 



Hartig and Somerville, Diseases of Trees, p. 177. 



Chrysomyxa abietis (Unger). The teleutospore state only 

 known, forming pale yellow spots on spruce leaves. The 

 formation of the pustules begins during the first year of 

 infection, reaches a certain stage of development, and then 

 passes into a resting condition until the following season, when 

 the development is completed. The teleutospores germinate 

 in situ during the month of May, and the secondary spores 

 infect the young leaves. 



Teleutospore pustules waxy, reddish-yellow, teleutospores 

 cylindrical, slightly thickened upwards, often branched, up 

 to 100 /x long, 9-12 /x broad, up to 12 cells in a mass. 



Causes but little injury. 



UREDO (Pers.) 



Sori generally orange-yellow, somewhat powdery, pseudo- 

 peridium absent ; uredospores produced singly at the tips of 

 fertile hyphae. 



The species are probably only forms not yet connected 

 with higher stages. 



Uredo vitis, Thiimen (= Uredo via/ae, Lagerh.), forms 

 small, yellowish, powdery pustules on cultivated vine leaves, 

 and has been recorded from the United States and the West 

 Indies. Spores piriform or broadly elliptical, verruculose, 

 orange, 18-30 X 15-18 /x, paraphyses curved. 



Lagerheim, Compt. Rend., 1890, p. 728. 

 Massee, Grevillea, 22, p. 119 (1893). 



Uredo cannae (Winter) is a destructive parasite to cultivated 

 cannas in the West Indies and other parts of the New World. 

 The fungus forms numerous small, orange spots on the leaves, 



