OF THE WISCONSIN ACADEMY OF SCIENCES, ARTS AND LETTERS STANFORD LIBRARY VOL. XIX, PART II MADISON, WISCONSIN 1919 NORTH AMERICAN ASCOCHYTAE A DESCRIPTIVE LIST OF SPECIES; COMPILED BY J. J. DAVIS, A list of North American species of Phyllosticta was published by Ellis & Everhart in 1900 and a similar list of species of Septoria, Phleospora, Rhabdospora and Phlyctaena prepared by Dr. George Martin and Mr. J. B. Ellis was issued in the Journal of Mycology, vol. III [1887]. The present list enumerates species of another of the genera of the same group. To the genus Ascochyta are referred species the sporules of which, as ordinarily observed, are uniseptate and so remain; those in which the sporules remain continuous nearly or quite to the time of full maturity becoming then uniseptate; species in which a majority of the sporules are continuous but a minority uniseptate. In the first two classes 2-3 septate sporules occur rarely. Species in which the sporules are uniseptate until maturity becoming then triseptate are referred to Stagonospora. Ascochyta is separated from Phyllosticta on the one side and Stagonospora on the other by somewhat shadowy lines. Some species that have been placed in this genus I am referring to Stagonospora and to Marssonina. 1 ASCOCHYTA ACHLYDIS Dearn. (Mycologia 8: 101–2.) Spots scattered, numerous small ones, 2mm., mostly sterile, and a few large ones 1 cm. or more in diameter with a central, sharply delimited, thin, arid, deciduous area surrounded by a diffuse dark red or purple brown border 1-5 mm. in width; pycnidia nearly concolorous with the arid area, epiphyllous although visible from the under side, 150-200"; sporules hyaline, 2-3 guttulate, obscurely uniseptate, rounded at the ends, 14-20 x 5-6/2μ. On leaves of Achlys triphylla. |