journal op amhtoal ream 
Voe. VIII Washington, D. C., February 26, 1917 No. 9 
A SQUASH DISEASE CAUSED BY CHOANEPHORA 
CUCURBITARUM 1 
By Frederick A. Wotr, 
Botanist and Plant Pathologist , North Carolina Agricultural Experiment Station 
INTRODUCTION 
It was noted during the past season (1916) that summer squashes in 
the vicinity of West Raleigh, North Carolina, were attacked by a phy- 
comycetous fungus, Choanephora cucurbitarum (B. and Rav.) Thaxter. 
Attention was directed to this fungus primarily because of the luxuriance 
of its fructifications on affected parts of squashes {Cucurbita spp.) and 
of the rapidity with which it destroyed such parts. A study was there¬ 
fore made of the development of the disease and of the morphology of the 
causal organism. Conidial, sporangial, chlamydosporic, and zygosporic 
stages have been developed, and there have been made certain observa¬ 
tions which are at variance with previously recorded facts relative to 
C . cucurbitarum and other species of the same genus. It is the present 
purpose, therefore, to record the results of this study as additional 
knowledge of this exceptionally interesting form and to indicate its 
importance as a parasite on the squash plant. 
HISTORY AND DISTRIBUTION OF THE FUNGUS 
This fungus has long been known to occur within the United States, 
having first been described in 1875 by Berkeley 2 as Rhopalomyces cucur¬ 
bitarum from decaying squashes collected in South Carolina by Ravenel. 
The organism has subsequently been found in other States, as noted by 
Thaxter 3 in his account of the genus Choanephora. Dr. Thaxter himseif 
collected the fungus on squashes at Waverley, Massachusetts, and on 
cultivated species of Hibiscus and a wild malvaceous plant at Eustis, 
Florida. He records the fact that the same plant is in the Curtis Her¬ 
barium at Harvard University under the name “Aspergillus cucur- 
biteus, Hillsborough, N. C., on squashes.” He further examined speci¬ 
mens of the same fungus on squashes sent from New York by Prof. Peck 
and from Ohio by Prof. Morgan. 
1 Published with the permission of the Director of the North Carolina Agricultural Experiment Station. 
2 Berkeley, M. J. Notices of North American fungi. In Grevillea, v. 3, no. 27, p. 109. 1875. 
* Thaxter, Roland. A New England Choanephora. In Rhodora, v. 5, no. 52, p. 97-102, pi. 46. 1903. 
Journal of Agricultural Research, 
Washington, D. C. 
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(319) 
Vol. VIII, No. 9 
Feb. 26,1917 
Key No. N. C.—3 
