44 
MILDEWS, RUSTS AND SMUTS 
ris), and U. montana. Distinguished by the few, club- 
shaped appendages, and the 2-spored ascus. 
Uncinula necator, Burr. The very thin, effused mycelium 
usually more or less persistent ; perithecia scattered, 
70—128 p diam,, averaging 98 p ; appendages variable 
in number and length, 7—32, brown in the lower half, 
wavy when long, tip usually with a considerable curl ; 
asci 4—9 ; spores 4—7, 18—25 x 10—12 p. 
Syn. Erysiphe tuckeri, Berk. 
Uncinula spiralis, Berk, and Curt. 
In England this species is known as the " Grape mildew.” 
The oidium form was first described by Berkeley as Oidium 
tuckeyi, in 1847, found on grapes from the neighbourhood 
of Margate. The ascigerous form has not yet been collected 
in this country, although it has been found sparingly in 
France, and is very abundant in the United States both on 
cultivated and wild vines (Vitis), also on species of Am- 
pelopsis, 
MICROSPHAERA, Lev. 
Perithecia globose or somewhat depressed ; asci several, 
containing 2—8 spores ; appendages, much branched in 
a definite manner at the tip (almost simple in one species). 
The species are readily recognised by the beautifully 
branched tips of the appendages. 
KEY TO THE SPECIES 
Parasitic on species of Berheris .... herberidis. 
Parasitic on species of Euonyynus .... euonymi. 
Parasitic on species of Astragalus .... astragali. 
Tips of appendages more or less closely 3—6 times forked, 
tips of ultimate branches recurved. Parasitic on many 
different hosts. alni. 
Parasitic on species of Lyciuin . mougeotii. 
Parasitic on species of Vida . haumleri. 
Parasitic on species of Rihes . grossulariae. 
Microsphaera berberidis, Lev. Mycelium usually soon 
disappearing, or sometimes persisting in thin white patches ; 
perithecia usually scattered, rarely in crowds, 90—125 p, 
diam. ; appendages 5—20, up to 2\ times as long as the 
diameter of the perithecium, tips regularly 4 times forked, 
branching rather close, ultimate branchlets not recurved ; 
asci 4—9 ; spores 3—6, usually 4, 18—22 X 9—ii p. 
Syn. Erysiphe penicillata, Link. 
