1918] 



DISEASES OF PLANTS. 253 



niou diseases of a number of ornamental plants, with suggestions for their 



control. 



Recent cultures of forest tree rusts, J. R. Weir and E. E. Hubert {rhyto- 

 patliology, 7 {1911), No. 2, pp. 106-109) .—'Reports are given of inoculation ex- 

 periments with a number of heteroecious rusts in which the host relationships 

 of Cronartinm coleosporoides, C. comptoniw, Melampsora medusw, M. bigelowii, 

 Puccinia strum pustiilatum, Gymnosporangimn tubtilatum, and O. nelsoni were 

 established. 



Pycnial stages of important forest tree rusts, J. R. Weir and E. E. Hubert 

 {Phytopathology, 7 {1917), No. 2, pp. 135-139, figsr 2). —The discovery of abun- 

 dant exudations of pycnospores on Pinus ponderosa and P. contorta caused 

 by Crunartiwm comandros led the authors to make a study of the pycnial stages 

 of C. coleosporoides, C. comptonke, and C. cerehrum. The pycnial stages of 

 these fungi were found and technical descriptions are given of these forms. 



In connection with these investigations, a species of Tuberculina was found 

 attacking the pycnial and recial stages of the different species of Cronartium on 

 Pinus. The occurrence of the Tuberculina is said not to have been sufficiently 

 abundant to indicate its economic importance. 



Notes on Razoumofskya campylopoda, G. G. Hedgcock and N. R. Hunt 

 {Phytopathology, 7 {1911), No. 4, PP- 315, 316).— As a result of inoculation ex- 

 periments in which seeds of R. campylopoda from Pinus sabiniana were trans- 

 ferred to 18 species of Pinus and also to Larix occidentaUs and Pseudotsuga 

 taxifolia, the authors were able to establish the dwarf mistletoe on Pinus 

 banksiana, P. bungeana, P. caribwa, P. pinea, P. sabinana, and P. Virginia na. 

 On P. bungeana and P. virginiana, dense witches' brooms were found around the 

 mistletoe-infected regions. On the other species, spindle-shaped swellings were 

 usually formed at the point of attack. All these species except P. sabiniana are 

 said to be new hosts for this species of mistletoe in this country. 



As the mistletoe is a western species which is able to attack vigorously a 

 number of species of eastern pines, the authors call attention to the desirability 

 of discouraging shipments of nursery stock from the Rocky Mountain and 

 Pacific regions to those further east, because of the possibility of introducing 

 the mistletoe to eastern plantations. 



Witches' brooms on hickory trees, F. C. Stewart {Phytopathology, 7 {1917), 

 No. 3, pp. 185-187, fig. 1).—A brief description is given of witches' brooms on 

 the shell bark hickory {Carya ovata) caused by the fungus Microstroma 

 juglandis. 



A Nectria parasitic on Norway maple, M. T. Cook {Phytopathology, 7 

 {1917). No. Ii, pp. 313, 314).— In a previous publication (E. S. R., 33, p. 249), 

 the author called attention to an attack on Norway maple in 1913 by a species 

 of Nectria. Later investigations have shown that the disease, although present 

 in subsequent years, was much less severe than in 1913. Besides the Norway 

 maple, the author has found the fungus attacking mulberry, on which it is 

 apparently a weak parasite. 



Sparassis radicata, an undescribed fungus on the roots of conifers, J. R. 

 Weir {Phytopathology, 7 {1917), No. 3, pp. 166-177, figs. 5>.— A description is 

 given of S. radicata n. sp., which is said to be widely distributed in the North- 

 west and often to attack the roots of Pseudotsuga taxifolia, Picea engelmanni, 

 Pinus monticola, and Larix occidentaUs. The mycelium of the fungus is said 

 to attack the base of the roots and later the wood, producing a yellow or brown 

 carbonizing rot. 



Needle rust on Pinus resinosa, P. Spaulding {Phytopathology, 7 {1917), No. 

 3, p. 225).— The author reports the occurrence in 1916 near Sharon, Vt., of 

 44073°— 18 5 



