Pseudomicrostroma juglandis
General description:
Colonies hypophyllous on poorly defined leaf spots, visible as large clusters of minute globose white fruit-bodies 320-450 µm diam. developing from stomata of the host. Basidia 8.5-12.5 µm long and 5.5-7 µm diam., clavate. Basidiospores (4-) 5.5-7.5 x 3-3.5 µm, ellipsoidal to cylindric-ellipsoidal, hyaline, aseptate, smooth, quite thick-walled.
Associations:
On living leaves of Juglans regia.
Distribution:
Throughout England and Wales, north to Durham. Apparently not recorded from Scotland.