46 CRANBERRY DISEASES. 



not been reported heretofore upon the American cranberry, though 

 different species of the genus attack various species of Yaccinium in 

 Europe and do considerable damage to the fruit. Under favorable 

 conditions for its rejjroduction and distribution this fungus might 

 prove a very serious enemy of the cranberry, and it is quite important 

 that steps should be immediately taken to eradicate it whenever and 

 "wherever it is found. 



The ascogenous stage of this fungus has not yet been found here, 

 though it probably occurs in the locality from which the conidia 

 were obtained. The conidia are borne in chains and measure 12 to 20 

 by 10 to 12 IX (PI. IV, fig. 23). They agree in all particulars with 

 Woronin's description and figures, except in the size of the spores. 

 In his description AVoronin gives 25 to 28 by 16 to 22 /* as the meas- 

 urements. 



Discosia artocreas (Tode) Fr. — This fungus has been found on 

 cranberry leaves from Cranmoor, Wis., which had been kept in the 

 laboratory in a moist chamber. Other specimens have been ob- 

 tained on leaves from near AVhitesville and Jamesburg, X. J., from 

 Wareham and Brewster, ]Mass., and from "West Virginia. The speci- 

 mens collected in the field were found in September and November. 

 This fungus has usually been regarded as a saprophyte and probably 

 does no particular injury to the cranberry plant. 



Plagiorhahdus oxycocci Shear.-* — This interesting fungus, which 

 it has been necessary to refer to a ncAv genus and species, was found 

 on cranberry leaves collected near Carver, Mass., in May, 1906. The 

 pycnidia are scattered, slightly erumpent, covered by the epidermis, 

 125 to 190 IX in diameter. The wall is not regular and well developed, 

 but is thicker and denser above. The interior is either simple or 

 somewhat chambered, but opens through a single ostiole (PL V, fig. 

 2). The pycnospores are hyaline or faintly colored in mass, and 

 are borne on slender, simple sporophores (PL V, fig. 3). They 

 measure 8 to 11 by 3 |U and are borne obliquely on the sporophore, 

 which is abstricted at its base and remains as an appendage (PL V, 

 fig. 3, a.)^ which is 10 to 15 by 0.75 jx. This species is closely related 

 to Plagiorhahdus crataegi Shear," which is found on the fruit of 

 Crataegus. It would therefore not be surprising if the species occur- 

 ring on the cranberry should also be found upon the fruit. 



Sporonema jnilvinatum Shear.-* — This fungus has been found 

 upon cranberry leaves in three instances — once on leaves collected in 

 Xew Jersey in November, 1905, and once on leaves from Olympia, 

 Wash., collected in October; also upon leaves from West Virginia 

 collected in June and kept in a sterile moist chamber. The pycnidia 

 are simple, dark broAvn, pulvinate. formed within the epidermis, the 

 outer wall of which adheres to their surface. They are 300 to 420 ix 



110 



