Phyllosticta concava Seaver 1922

Phyllosticta concava Seaver, sp. no v
Spots very variable in size, often reaching a diameter of several cm., cinereous or blackish the infected area much depressed and concave, with a strongly elevated rim, similar in appearance on both sides of the leaf-like stem, the infected tissue becoming very thin and often breaking out; pycnidia numerous, thickly scattered over the infected spot, reaching a diameter of 150-200 m; spores minute ellipsoid or rod-like, about 1-1.5 X 4 /x.
Causing large dead spots similar to those of Sphaerella Opuntiae Ellis & Ev.
On Cactaceae:
Opuntia sp., Bermuda. _
Type collected in Bermuda by Stewardson Brown, N. E. Britton, and Fred J. Seaver, November 29-December 14, 1912 (reported erroneously, Mem. N. Y, Bot. Gard. 6: 509, as P. Opuntiae Sacc. & Speg.)