MILDEWS, RUSTS AND SMUTS 
27 
[Parasitic on plants belonging to the order Santalaceae 
Thesium. Patches small, whitish; conidia almost 
globose, 15—20 X 14—17 [x, colourless. 
thesii, Lagerh.] 
[Parasitic on plants belonging to the order Fumariaceae, 
Corydalis. Patches dingy white, or tinged lilac; 
conidia elliptical, tinged lilac, 24—30 x 16—20 p,; 
oospores globose, 32—37 p, diam. corydalis, De Bary.] 
[Parasitic on plants belonging to the order Campanulaceae. 
Patches small, greyish-white; conidia pear-shaped, 
almost colourless, 20—27 X 13—17 p,, 
niessleana, Berl.] 
[Parasitic on plants belonging to the order Zygophyllaceae. 
Tufts dense, white or greyish ; conidia broadly pear- 
shaped, 21—^30 X 20—24 p,, colourless. 
trihulina, Pass.] 
A. Divaricatae 
Peronospora violacea, Berk. Forming minute, scattered, 
soft, pale dingy lilac patches ; mycelium with vesiculate 
haustoria ; conidiophores short, erect, 150—300 X 25—35 
p,, base somewhat thickened, 5—7 times forked upwards, 
primary branches few in number, erect, ultimate branchlets 
short, erect, all the branches fairly straight, angles formed 
by the branching, sharp; conidia elliptical or slightly 
narrower towards the base, pale dingy lilac, 30—^50 x 
16—25 p,; oosphere with a fairly thick wall; oospore 
subglobose, wall 5—8 p, thick, becoming brown, more or 
less wrinkled, 30—40 p, diam. 
This may possibly prove to be identical with a fimgus 
named Botrytis violacea, by Leveille (Ann, Sci. Nat., 1846, 
p. 298), said to have erect hyphae, continuously forked, and 
bearing smooth, violet conidia. It occurred on flowers 
of Pyrethrum arvense, and on leaves of Lathyrus palustris, 
in France. 
Peronospora violacea is parasitic on the petals of various 
plants belonging to the order Dipsaceae, more especially 
on those of Scabiosa arvensis. Petals that are infected 
soon become flaccid and assume a brownish tinge. 
The vesicular or small, pear-shaped haustoria, possessed 
by this species, are very unusual in the genus. 
Peronospora valerianae. Trail. Patches of mildew not 
well defined, greyish-violet; conidiophores 5—6 times 
forked, ultimate branchlets 7 p, long, spreading, slightly 
curved, scarcely tapering; conidia obovate, or obovate- 
