MILDEWS, RUSTS AND SMUTS 
31 
Syn. Peronospora sphaeroides, W. G. Sm. 
Peronospora grisea, var. trifoUi, Rabenh. 
Parasitic on the living leaves of leguminous plants, as 
Trifolium, Ononis, Medicago, Melilotus, Lotus, Coronilla, 
Astragalus, Orobus, etc. 
Usually covering the entire under surface of the leaf, 
with a very delicate greyish film. 
Peronospora grisea, De Bary. Forming dense, velvety, 
greyish-violet patches; conidiophores tufted, 250—^400 
X 8 — 10 p, 5 — 7 times forked above, branches tapering 
upwards, spreading, more or less curved, ultimate branch- 
lets straight or curved ; conidia elliptical, tip rounded 
and blunt, 20—30 X 15—22 p, pale dingy lilac ; oospore 
globose, brown, wall densely but very minutely warted, 
sometimes smooth, 35—^46 p diam. 
Syn. Botrytis grisea, Unger. 
Growing on the under surface of leaves of plants belonging 
to the order Scrophulariaceae, as Veronica beccabunga, 
V. serpyllifolia, V. scutellata, V. arvensis, V. verna, V. 
triphylla, V. hederaefolia, V. anagallis, etc. 
Peronospora violae, De Bary. Forming dense, felt¬ 
like effused greyish-lilac patches ; conidiophores tufted, 
about 300 X 8 p, 3—7 times branched upwards, ultimate 
branchlets short, tapering, spreading ; conidia elliptical, 
somewhat warted at the tip, 20—27 X 14—19 p, pale lilac ; 
oospore somewhat angularly globose, yellowish-brown. 
Syn. Peronospora effusa, var. violae, Fuckel. 
Parasitic on leaves of plants belonging to the order 
Violaceae, as Viola tricolor, V. riviana, V. biflora, etc. 
Exceptional in having the tip of the conidium slightly 
apiculate. 
Peronospora arborescens, De Bary. Forming dense, 
widely effused patches, at hist white, then greyish-violet; 
conidiophores tufted, 300—800 X 10—12 p, forked 6—10 
times upwards, branches more or less wavy, spreading, 
becoming thinner upwards, ultimate branchlets slender, 
pointed, more or less curved ; conidia subglobose, 15—24 
X 15—20 p, colourless or tinged lilac ; oospores subglobose, 
wall brown, very minutely streaked, 25—35 p diam. 
Syn. Botrytis arborescens, Berk. 
Peronospora papaveris. Tub 
Parasitic on the leaves of plants belonging to the order 
Papaveraceae, as Papaver rhaeas, P. dubium, P. somni- 
ferum, P. argemones, etc. 
