336 



Mycologia 



The needle-blight of white pine is said by J. H. Faull, who 

 has observed and investigated it for several years, to be physio- 

 logical in its nature. Warm, bright days in winter, when the 

 ground is frozen and the roots inactive, cause excessive loss of 

 water from the tips of the leaves and they dry out and become 

 brown. 



A paper by E. B. Mains on unusual rusts of Nyssa and Urti- 

 castrum, published in the American Journal of Botany for 

 November, 1921, includes a description of the new genus Aplo- 

 spora, based on Uredo Nyssae, and two new combinations, 

 Aplospora Nyssae (Ellis & Tracy) Mains and Cerotetium Dicen- 

 trae (Trel.) Mains & Anderson. 



Greenhouse diseases observed at Macdonald College, Quebec, 

 were briefly noted by B. T. Dickson in a recent annual report of 

 the Quebec Society for the Protection of Plants. The chief 

 diseases discussed are : carnation rust ; cineraria dwarfing, mosaic, 

 and distortion ; snapdragon rust ; sweet pea powdery mildew ; 

 tomato mosaic and a leaf-mold ; and violet leaf-spot. 



A bud-rot of peonies, which has been observed by various per- 

 sons during the past few years, was described by H. W. Thurston, 

 Jr. & C. R. Orton in Science for 192 1. Just as the flower buds 

 are swelling, they turn black and decay, the disease often extend- 

 ing to the upper leaves and several inches of the stalk. Infected 

 material yielded a species of Phytophthora closely related to P. 

 infestans. 



A bacterial disease of gladiolus, caused by Bacterium mar- 

 ginatum, was described by L. McCulloch in Science for 1921. 

 It is abundant in and about Washington, D. C, and probably 

 occurs also in Illinois and California. The affected leaves show 

 elliptic spots that are at first rusty-red, then dull-brown or 

 purplish. Moist, warm weather is very favorable to the growth 

 of the pathogen, often resulting in the decay of the entire plant 

 above ground. 



