Other deciduous broadleaves (notably poplar).
Can be found across the entire structure of the tree, from the base of the stem up into the higher crown. Often restricted to dysfunctional areas – notably old pruning wounds or sites of storm damage and limb loss.
Species complex. Perennial. Tough and woody. Grey on the upper surface when young and becoming a purplish black – sometimes greening slightly. Margin and underside a velvety grey-brown. Spore white. Flesh rustic brown. Variable in size and abundance – older fruiting bodies can become quite large.
Attributed with a selective white rot of the wood. Understood to be able to act parasitically. Extensive colonisations on willow or where fruiting is on the main stem or on a scaffold limb should therefore be treated with a degree of caution and could be quantified with decay detection tools, where necessary given the weak wood properties of willow and the ability for this fungus to form extensive horizontal decay columns. Localised examples – such as on aerial deadwood or upper crown storm damage – may prompt less concern, though a climbing inspection may be necessary to assess the area in question.