30 
MILDEWS, RUSTS AND SMUTS 
emerging singly through the stomata, 500—700 X 10—12 
[i, 7—9 times forked above, primary branches suberect, 
the remainder spreading, often slightly curved ; conidia 
elliptical, tip rounded, faintly tinged lilac, 20—30 X 14—17 
(x ; oosphere globose, with a 'thin, colourless wall; oospore 
globose, with a thickish bay-coloured wall, having thin 
ridges anastomosing to form a very small-meshed network, 
36—^44 p, diam. 
Syn. Peronospora galii, Fuckel. 
Peronospora sherardiae, Fuckel. 
Parasitic on plants belonging to the order Galiaceae, as 
Galium verum, G. aparine, G. palustris, Asperula odorata, 
Sherardia arvensis, etc. 
Peronospora alsinearum, Casp. Tufts of mildew dense, 
broadly effused, greyish-white ; conidiophores 250—350 
X 8—9 (JL, repeatedly forked above, primary branches 
straight, the remainder more or less curved and spreading ; 
conidia elliptical, proportional length to breadth variable, 
tip blunt, 22—30 X 15—19 (JL, tinged lilac ; oosphere with 
a thin, colourless wall; oospore globose, with a thick yel¬ 
lowish-brown wall covered with a network of raised lines, 
40—45 (JL diam. 
Syn Peronospora conferta, Unger. 
Peronospora lepigoni, Fuckel. 
Peronospora tomentosay Fuckel. 
Peronospora scleranthi, Rabenh. 
Peronospora ohovata, Bon. 
Parasitic on plants belonging to the order Caryophylla- 
ceae, as Cerastium arvense, C. glomeratum, C. semidecan- 
drum, C, triviale, Stellaria media, Scleranthus annuus, Sper- 
gula arvensis, S. rubra, etc. 
Differs from Peronospora arenariae and P. dianthi in the 
larger conidia, and in the very small network on the wall 
of the oospore. 
Peronospora trifoliorum, De Bary. Forming dense, 
broadly effused greyish-lilac patches; conidiophores 
tufted, crowded together at the base, 300—450 (x long, 
6—7 times forked above, rarely branching in threes, primary 
branches almost straight, secondary branches spreading, 
and more or less curved, ultimate branchlets curved; 
conidia broadly elliptical, 18—20 x 15—20 (x, tip very 
blunt and rounded, pale dingy lilac ; oospores globose, 
wall smooth, brown, 24—^38 (x diam. 
