MILDEWS, RUSTS AND SMUTS 45 
Differs from M. grossulariae in the longer appendages, 
and in the somewhat smaller spores. 
Parasitic on the leaves of barberry {Berberis vulgaris), 
and on those of Berber is (Mahouia) aquifolium. 
Microsphaera euonymi, Sacc. Patches of mycelium 
usually on the under surface of the leaves, generally soon 
disappearing ; perithecia usually more or less crowded ; 
appendages 6—14, 2—5 times as long as the diameter of 
the perithecium, tips 3—5 times forked, ultimate branch- 
lets usually straight ; asci 3—7 ; spores 3—5, 20—23 X 
10—12 p. 
Syn. Microsphaera comata, Lev. 
Marked by the weak, long appendages becoming tufted 
together and lying on the leaf. 
Parasitic on the leaves of Euonymus europaeus and E. 
verrucosus. 
Microsphaera astragali, Trev. Mycelium usually soon 
disappearing ; perithecia usually crowded, rarely scattered, 
95—146 [jl diam. ; appendages 5—18, 4—10 times as long 
as the diameter of the perithecium, rather weak, wavy, 
forming a tuft, tip simple, or once or twice forked ; asci 
5—12 ; spores 3—6, usually 4, 20—23 X 10—12 p. 
Syn. Microsphaera holosericea, Lev. 
Parasitic on the leaves of Astragalus glycyphyllos, and 
other species of Astragalus. 
Microsphaera alni, Salmon. Mycelium sometimes soon 
disappearing, at other times persistent and effused ; peri¬ 
thecia scattered or crowded, 66—no p, diam. ; appendages 
very variable in number and length, 4—-26, usually about 
times as long as the diameter of the perithecium, tips 
more or less closely 3—6 times forked, ultimate branches 
always curved backwards ; asci 3—8 ; spores 4-—8, 18— 
23 X 10—12 p. 
Syn. Microsphaera hedwigii, Lev 
Microsphaera penicillata, Lev. 
Salmon says this is the most variable species of the 
Erysiphaceae, and I quite believe it, he has devoted 27 
pages to the elucidation of this species and its varieties, 
notwithstanding which, I am by no means certain that I 
have grasped the essential features of the species, and must 
be content to attribute to it, any Microsphaera found 
parasitic on species of Alnus or Betula. 
