356 PLANT DISEASES 



Epispore of oospore smooth. 



Peronospora schleideni, Unger., Bot. Ztg., 1847, p. 315. 

 Forming greyish-lilac tufts; conidiophores erect, 250- 

 400 /* high, branched alternately, or in a dichotomous 

 manner, ultimate and penultimate branches strongly 

 curved; conidia obovate, apex obtuse or subacute, pale 

 dingy violet, 44-52X22-25 /A; oospores broadly elliptical 

 or globose, epispore thin, smooth. 



Peronospora trifoliorum, De Bary, Ann. Set. Nat., ser. iv. 

 vol. xx. p. 117 (1863). Conidiophores 350-450 p. high, 

 forming broadly effused tufts, equally or irregularly 6-7 

 times dichotomous, rarely trichotomous, primary branches 

 4-5 times dichotomous ; ultimate branchlets pointed, 

 slightly curved ; conidia ellipsoid, about 21 //. diam., wall, 

 pale violet; oospores globose, epispore thick, smooth, 

 brown, 25-34 p. diam. 



Peronospora schachtii, Fuckel, Symb. Myc., p. 71 

 (1869-70). Forming dense grey tufts; conidiophores 

 erect, 6-8 times dichotomous, primary branches 2-5, short, 

 ultimate branchlets generally unequal, short, straight, 

 wide - spreading, obtuse ; conidia ovate, pale umber, 

 20-24X15-18 p.; oospores globose, wall thick, smooth. 

 Very closely allied to P. effusa. 



Peronospora violae, De Bary, Ann. ScL Nat., ser. iv. 

 vol. xx. p. 125. Forming somewhat dense, clear, pale 

 violet tufts ; hyphae rather short, about 300 /z, 4-7 times 

 dichotomously branched, ultimate branchlets short, acute, 

 deflexed; conidia elliptical, blunt, shortly apiculate, aver- 

 aging 25 x 18 p, pale violet; oospore with a golden-brown 

 epispore. 



Peronospora cubensis, Berk, and Curt., Journ. Linn. Soc 



