1 1 2 British Fu^m. 



^> 



term mildew. Distinguislied from Phytophthora by 

 the absence of vesiculose swellings on the branches of 

 the gonidiophore. 



Plasmopara entospora, Schroet. 



Gonidiophores in small tufts on the under-surface 

 of the leaf, whitish, becoming brown, cylindrical, 

 aseptate, 140-160x10-14 /x, base slightly inflated, 

 and furnished with a few slender mycelial branches, 

 apex slightly inflated and giving origin to a few (8 — 

 12) slender sterigmata, slightly incrassated at the tip=?, 

 10-12x1-2 fji, gouidia elliptical, papillate, very 

 pale yellow, 20-25 x 12-14 /a ; microgonidia elliptical, 

 hyaline, 5-6x 3'5-4 //,; oogonia globose, containing a 

 single oospore with a thick membrane. 



Plasmopara entospora, Schroet. Krypt. Fl. Schles. 

 Pilze, p. 237 ; Sacc. Syll. vii. 805. 



On under surface of leaves of Erigeron Canadensis , 

 and on Aster. Rare. 



Plasmopara pygmcea J Schroet. 



Mycelium thick, variously constricted, haustoria 

 minute, more or less piriform ; gonidiophores slender, 

 often in fascicles of 2 — 6, simple, or branched above, 

 branches simple or once or twice dichotomous, tips sur- 

 mounted by 2 — 4 short, cylindrico-conical branchlets, 

 which are truncate after the gonidia fall away ; 

 gouidia elliptical, size variable, 18-25 x 15-20 fx, apex 

 broadly and obtusely papillate ; oogonium globose, 

 45-55 /Lt, epispore thin, yellowish-brown, smooth or 

 minutely rugulose, endospore thick. 



Plasmopara pygmcea, Schroet. Krypt. Fl. Schles. 

 p. 239 ; Sacc. Syll. vii. 807. 



