Basidiocarps annual. sessile, with a pleasant anise odor when fresh, usually solitary, dimidiate or elongate, up to 14 cm wide: pileus surface cream coloured to buff, finely tomentose to glabrous, azonate, smooth, margin rounded; pore surface cream coloured to pale buff, the pores circular to angular, 2-3 per mm, dissepiments thick and entire; context white to cream coloured, soft-corky, zonate, up to 3.5 mm thick; tube layer concolorous with or slightly darker than the context, up to 1 cm thick.
Hyphal system trimitic; contextual generative hyphae thin-walled, hyaline, rarely branched, with clamps, 3-5 µm in diam; contextual skeletal hyphae thick-walled, hyaline, nonseptate, rarely branched, 4-8 µm in diam; contextual binding hyphae thick-walled, much branched, 2.5-5 µm in diam; tramal hyphae similar.
Cystidia and other sterile hymenial elements lacking.
Basidia clavate, 4-sterigmate, 22-30 × 6-7 µm, with a basal clamp.
Basidiospores cylindric, thin-walled, hyaline, smooth, negative in Melzer’s reagent, 8-12 × 4-4.5 µm.
Type of rot. White heartrot of living hardwoods and also on stumps.
Cultural characteristics. See Nobles, 1948, 1958, 1965; Stalpers 1978.
Sexuality. Heterothallic and tetrapolar (Vandendries 1933; Nobles, 1965).
Substrata. In Europe almost exclusively on Salix (especially S. fragilis) and Populus spp. (especially P. alba), but also collected on Aesculus, Betula, Carpinus, Fagus, Fraxinus and Malus.
Distribution. Widely distributed in Europe to southern part of Fennoscandia. Circumpolar in the temperate zone to Eastern North America.