Microstroma album  

Colonies hypophyllous on poorly defined leaf spots or broadly developing on apparently unaffected leaf tissue, visible as scattered clusters of white fruit-bodies 400-600 µm diam., with columns of thick-walled basidia 15-20 µm long and 3-4 µm diam., ± cylindrical but with swollen, clavate apices. Basidiospores 6-7.5 x 2.5-3 µm, ellipsoidal to cylindric-ellipsoidal or ovoid, hyaline, aseptate, smooth, thin-walled.