Community find

Violet-toothed Polypore

Trichaptum biforme

Group

polypore/crust fungus

Spore print

White

Size

Individual caps are 1-7 cm wide and 1-3 mm thick; often found in massive tiered colonies covering large sections of logs.

Season

Year-round, with active growth in spring, summer, and fall.

Habitat

Grows in large, overlapping clusters on the deadwood of deciduous hardwood trees, occasionally on conifers.

Distribution

Widely distributed throughout North America, Europe, and Asia.

Key characteristics

Zoned, shelf-like caps with a hairy or velvet-like upper surface and a distinct violet-colored pore surface on the underside (fading to brown with age).

Fruiting body

Caps are fan-shaped, semicircular, and thin. The top surface is greyish-white with concentric zones of color and a lilac margin when young. The fertile surface (undercut) is composed of angular pores that eventually become tooth-like or ragged, typically showing a vibrant violet or purple hue.

How to recognise it

Look for the intense violet color on the margin and the pore surface. Note whether the 'pores' have broken down into jagged teeth, which is a key diagnostic feature of the genus Trichaptum.

Look-alikes

Trichaptum abietinum (grows on conifers, smaller), Trametes versicolor (Turkey Tail - has real pores and lacks the violet underside color).

Ecological role

Saprophytic; it causes white rot in the sapwood of dead or dying hardwood trees.

Notes

This fungus is often a host for other fungi and beetles. It is one of the most common bracket fungi found in Eastern North American forests, playing a significant role in nitrogen cycling by decomposing wood.