Hedgcock and Hunt : Dothichiza populea in the U. S. 305 
Description of the Fungus 
The following description of Dothichisa populea Sacc. &Briard 
is based on specimens from ten different collections from seven 
different states. The spore measurements are based on lOO 
spores, lo from each collection. 
Pycnidia, numerous in the bark, at first in pustules covered by 
the epidermis of the host, rupturing at the top when mature, the 
tops of the pustules later breaking away, leaving pseudo-acervuli, 
lens shaped to subspheroid before rupturing, often irregular in 
shape, ^ to Ij4 mm. in diameter; walls black, with irregular sur- 
face at the base on the inside; spore masses ejected in cylindric 
tendrils, usually short, creamy to tawny olive or walnut brown in 
color ; spores subglobose to ovoid, or rarely ellipsoid, smooth, 
hyaline when viewed singly, smoky in mass; 9.5-17 X 6.7-12.7/u., 
averaging 12. i X8.6/.t; germinating at the smaller or basal end. 
Spores of Dothichiza populea from No. 1100, Krieger, Fungi 
Saxonici Exsiccati, on Popuhts nigra, measure as follows: lo.i- 
12.2 X 7-3-10.2 /A, averaging 11.6 X 9-i It m.ust be noted that 
these spores were measured from dried material mounted in 
water, while those on which our description is based contain the 
measurements from five fresh specimens, three partially dried 
specimens, and two thoroughly dried specimens. The dried 
specimens yielded slightly smaller measurements. 
Distribution of the Fungus 
Dothichiza populea has been collected in the United States on 
the following hosts : 
Popidus nigra 
New Hampshire: Hanover, by J. L. Richards, June, 1915 
(P.D.S.^ 662). 
Massachusetts: West Lynn, by J. L. Richards, June, 1915 
(P.D.S. 611). 
New Jersey : IMorrisville, by George G. Hedgcock, June, 1916 
(F.P.^ 22353). 
Pennsylvania : Delaware Water Gap, by N. M. Goodyear, May, 
1916 (F.P. 22362). By George G. Hedgcock in 1916, West 
3 P.D.S., Plant-Disease Survey. 
4 F.P., Forest Pathology. 
