May, 1910.] 
The Ohio Powdery Mildews. 
J 73 
Microsphaera alni vaccinii (Schw.) Salm. Perithecia scat- 
tered, 70-145 y in diameter; cells 10-20 y\ appendages 4—22, 
23^-8 times diameter of perithecium, colorless, or darker at 
base, nonseptate, apex 2-4 times dichotomously branched, ulti- 
mate branchlets recurved; asci 2-16, 45 x 28-72 x 38 y; spores 
4^6, 18 x 10-22 x 13 y. 
Host plants in Ohio Herbarium: Vaccinium vacillans, Portage Co., 
Lake Co., E. Claassen, Vaccinium corymbosum, Portage Co., E. Claassen; 
( atalpa bignonoides, Columbus, C. M. Weed, Oberlin, F. D. Kelsey, 
Toledo, F. D. Kelsey. 
Microsphaera russellii Clinton. Perithecia scattered, 70-118 
y in diameter; cells 6-14 y\ appendages 5-14, 3-7 times diameter 
of perithecium, septate, colored nearly to apex, 2-4 times 
dichotomously branched, branches irregular and lax, tips not 
recurved, primary branches long; asci 4-9, short-stalked, 42 x 24- 
56 x ‘32 y, spores 4, IS x 10-22 x 12 y. Appendages not branched 
until fully mature. 
Host plants in Ohio Herbarium: Oxalis stricta, Hamilton Co., W. H. 
Aiken, Columbus, W. A. Kellerman. 
Otherwise reported in Ohio: Oxalis recurva, E. M. Wilcox. 
Microsphaera diffusa C. & P. Perithecia 55-126 y in diam- 
eter; cells 10-20 y \ appendages 4-30, 1-1 2-7 times diameter of 
perithecium, sometimes septate in lower half, colorless, thicker 
walled toward base, apex 3-5 times irregularly dichotomously 
branched, tips swollen and not recurved; asci 4-9, 48 x 28- 
60 x 30 y, with very short stalk; spores 4, 18 x 9-22 x 11 y. 
Host plants in Ohio Herbarium: Meibomia canescens, Meibomia 
dillenii, Cuyahoga Co., E. Claassen; Desmodium sp., Franklin Co., F. L. 
Stevens; Desmodium nudiflorum, Columbus, C. M. Weed. 
Otherwise reported in Ohio; Desmodium canescens, Columbus, C. M. 
Weed, F. Detmers, A. D. Selby. 
Microsphaera grossulariae (Wallr.) Lev. Perithecia 65-130 y 
in diameter; cells 14-20 y \ appendages 5-22, 1-1 M times diam- 
eter of perithecium, colorless, nonseptate, thicker walled toward 
base, apex 4-5 times dichotomously branched, branches close 
and regular, and ultimate branches long, giving a digitate 
appearance ; asci 4-10, short stalked, 40 x 28-62 x 38 y; spores 4-6, 
20 x 12-28 x 16 y. 
Host plants in Ohio Herbarium: Sambucus canadensis, Columbus, 
W. A. Kellerman, Sugar Grove, W. A. Kellerman. 
Phyllactinia Lev. 
Phyllactinia corylea (Pers.) Karst. Perithecia 150-275 y in 
diameter; cells 10 to 15 y; appendages 8-12, equatorial, length 
Y\ to 4 times diameter of perithecium, sharp-pointed, with bul- 
bous base; asci 5-20, stalked, 30 x 90 y \ spores 2, 14 x 18 y. 
