. Fungous diseases of plants, with chapters on physiology, culture methods and technique . Exp. Sta. Rept. (1907): 369-396. pis. 23-32. Occurrence. Of the several species of Coleosporium havinguredospores and teleutospores on species of Compositae, there isnone of such common occurrence throughout North America asthe species here discussed. To this species are referred the orangerusts of many species of Aster and Solidago (golden-rod). It in-cludes also as hosts representatives of several other genera, amongwhich is the cultivated aster {CallistepJuis hortensis). This fungusis by many regarded
. Fungous diseases of plants, with chapters on physiology, culture methods and technique . Exp. Sta. Rept. (1907): 369-396. pis. 23-32. Occurrence. Of the several species of Coleosporium havinguredospores and teleutospores on species of Compositae, there isnone of such common occurrence throughout North America asthe species here discussed. To this species are referred the orangerusts of many species of Aster and Solidago (golden-rod). It in-cludes also as hosts representatives of several other genera, amongwhich is the cultivated aster {CallistepJuis hortensis). This fungusis by many regarded as identical with a species occurring wide-spread in Europe upon Senecio. 436 FUNGOUS DISEASES OF PLANTS The genus Coleosporium is to be considered entirely heteroe-cious, and whenever secidial stages are known in the Hfe cycle,they occur on species of Pinus, and are referable to the formgenus Peridermium. The aecidial stage of the species here discussed has recentlybeen found through inoculation experiments to be a form known as Pe ride rni iu vtacicolum occurringon leaves of Pimcs. rigida in several of the northeasternstates. The Euro-pean form occursupon branches andstems of Pinussylvestris. The fungus. Theuredo and teleutostages are merelyconspicuous bytheir color, and inthis particular in-stance the aecidialstage is by nomeans forms orspecies of Peri-dermium, however,may produce considerable swellings upon their hosts. According to Clinton the infection of young pine leaves maytake place in spring, the aecidia resulting the following year. Itwould appear that the Peridermium is inessential for the continu-ous propagation of the rust upon composites in the United States,since the uredo stage is produced practically throughout the winteron leaves of the basal rosettes. The spermogonia appear upon the needles in autumn, but theaecidia are not developed until spring. They occur on both sur-faces of the leaves in slightly discolored spots. They are crumpent, Fig
Size: 1427px × 1751px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherbostonnewyorketcgi
