36 
IOWA ACADEMY OF SCIENCE 
Sulphur and Bordeaux mixture are used as remedies against the 
present species. 
Uncinula circinata Cooke & Peck. 
See Plate II. 
Uncinula circinata, Cooke & Peck. Bessey, Prel. List, Ames Flora; Hitch- 
cock, Partial List Iowa Powdery Mildews; Fink, Blights, etc., of Fayette. 
Hypophyllous; mycelium usually evanescent; perithecia usually scattered, 
160-225 micra in diameter, rarely smaller; cells irregular, 10-14 micra wide; ap- 
pendages very numerous, usually crowded, their length rather less than the 
diameter of the perithecium, simple, hyaline, apex simply uncinate; asci 9-26, 
68-86x29-40 micra; spores 8, sometimes only 7, 18-22x10-14 micra. 
On Acer saccharinum, L. Ames, Oct., 1894 (Carver) ; *Belle Plaine, Sept., 
1886 (Hitchcock) ; Decatur Co., Oct. 28, 1905 (Anderson) ; Decorah, Oct., 
1879 (Holway) ; Iowa City, Oct. 7, 1893 (Bloom). 
On Acer saccharum, Marsh. *Fayette, Sept., 1893 (Fink). 
A very beautiful species under the microscope. A specimen 
labeled TJ. circinata on Acer saccharum in Prof. Fink’s herbarium 
proved to be Phyllactinia corylea. 
Uncinula parvula Cooke & Peck. 
Amphigenous; mycelium evanescent; perithecia usually hypophyllous, scat- 
tered, 86-122 micra in diameter, cells about 10 micra wide; appendages nu- 
merous 50-160, %-% times the diameter of the perithecium, simple, hyaline, 
apex simply uncinate; asci, 5-8, 50-64x34-38 micra; spores 4-7, usually 6, 
20-24x10-12 micra. On Celtis occidentalis L. Ames, Sept. 15, 1878 (Bessey). 
Uncinula macrospora Peck. 
Uncinula intermedia Berk. & Curt. Bessey, The Erysiphei. 
Uncinula macrospora Peck. Bessey, The Erysiphei; Hitchcock, Partial List 
Iowa Powdery Mildews; Fink, Blights, etc., of Fayette. 
Amphigenous; mycelium evanescent or subpersistent, often forming circum- 
scribed patches on the upper surface of the leaf; perithecia gregarious or scat- 
tered, 95-165 micra in diameter; cells about 10 micra wide; appendages 50-130 or 
more, A -1 times the diameter of the perithecium ; colorless ; aseptate ; apex 
simply uncinate, rarely subhelicoid; asci 8-14 or more; often curved, 54-65x 
29-35 micra; spores 2, 30x15-18 micra. 
On Ulmus americana L. *Cedar Rapids, Sept., 1886 (Hitchcock) ; Decatur 
Co., Oct., 1905 (Anderson) ; Decorah, Sept., 1879 (Holway) ; Fayette, Sept., 
1894 (Fink); Johnson Co., Sept., 1885 (Macbride). 
On Ulmus racemosa Thomas. Decatur Co., Oct. 28, 1905 (Anderson). 
On Ulmus americana I have found the perithecia evenly dis- 
tributed over the under surface of the leaf with the mycelium com- 
pletely evanescent and I have also found it with mycelium sub- 
persistent in circumscribed patches on the upper surface of the leaf. 
