48 
MILDEWS, RUSTS AND SMUTS 
KEY TO THE SPECIES 
* Spores normally 2 iri an ascus. 
Haustoria lobed ; spores produced in the ascus on the 
living host-plant. galeopsidis. 
Haustoria not lobed ; spores not produced in the ascus on 
the living host-plant . cichoracearum. 
** Spores more than two in an ascus. 
Parasitic on grasses. graminis. 
Parasitic on species of Cornus . toriilis. 
Parasitic on Polygonum, Achillea, Aconitum, and numerous 
other plants, but not on Cornus, nor on grasses. 
polygoni. 
Erysiphe gaelopsidis, D.C. Mycelium soon disappearing 
or somewhat thin and persistent ; haustoria distinctly 
lobed ; perithecia scattered or gregarious ; appendages 
variable, mixed with the mycelium ; asci rather numerous ; 
spores 2 in number, not produced in the asci on the living 
host-plant, but the year following on the dead plant, 
averaging 20 x 12 p. 
Syn. Erysiphe lamprocarpa, Kickx. 
Parasitic on the leaves of various labiate plants, as 
Galeopsis, Ballota, Galeohdolon, Stachys, etc. 
Characterised by having lobed haustoria, and the absence 
of spores on the ascus on the living plant. 
Erysiphe cichoracearum, D.C. Mycelium usually soon 
disappearing, sometimes persisting, usually white, rarely 
tinged pink ; perithecia gregarious or scattered, 80— 140 p 
diameter; appendages very variable, usually vaguely 
branched and interwoven ; asci about 10—^15 ; spores 2, 
rarely 3, 20—28 X 12—20 p, averaging 24 X 14 p. 
Syn. Erysiphe lamprocarpa, Kickx. 
Erysiphe Linkii, Lev. 
Erysiphe Montagnei, Lev. 
Agreeing with E. galeopsidis in having 2 spores in the ascus, 
but differing in the larger spores. 
Parasitic on numerous plants belonging to many different 
orders, as Artemisia, Achillea, Ballota, Campanula, Cicho- 
rium, Crepis, Galium, Hieracium, Solanum, etc. 
Erysiphe graminis, D.C. Mycelium more or less persis¬ 
tent, forming whitish patches, often becoming tinged 
brown or grey ; perithecia scattered or gregarious, depressed 
large, 135—280 p diam. ; appendages vague and rudi¬ 
mentary ; asci numerous, 9—30 ; spores 8, rarely 4, 
