26 STATE HORTICULTURAL SOCIETY 



252. P. polygon l, Thueni. 



On Polygonum avicidare and on P. dumertorum, var. 

 soandens. 



253. P. potentilla, DeBy. 



On Potentilla norvegica. 



254. P. pygmasa, linger. 



On Anemone dichotoma. 



255. P. sordida, Berk. 



On Scrophularia nodosa. 



256. P. trifoliorum, DeBy. 



On tncia amerkana and on Astragalus canadensis. 



257. P. wr&eo!, DeBy. 



On Laportea canadensis. 



258. P. vitkola, DeBy. 



On Fi7is raparia. On cultivated grapes. Brown rot. 



259. P. view, (Berk.) DeBy. 



Abundant in latter part of May and early June on Vicia 

 americana. 



260. P. arthuri, Farlow. 

 Abundant on (Enothera biennis. 



261. P. effusa, (Grev.) Rahenh. 



Abundant on Chenopodium album in May and June. 



262. P. euphorbias, Fuckel. 



Abundant on Euphorbia preslii and £\ maculata. 



263. P. aWa, Fuckel. 



Abundant on Plantago major. 



264. P. cubensis, B. & C. 



Mildew of squash and cucumbers, usually under glass. 

 Pythium, Pringsb. 



265. P. de baryanum, Hesse. 



Attacks seedling plants, and is called by gardeners 

 "damping-off." 



