Shaggy Bracket

The Shaggy Bracket is one of the most conspicuous annual brackets of temperate broadleaved trees, forming heavy cushion-like shelves on trunks and large limbs, often several metres above the ground. When young it is vividly rusty orange and covered in a dense coat of coarse hairs, giving it the shaggy texture that names it; by late autumn the same bracket has blackened, hardened and slumped, and it may hang on the trunk right through the winter.

The genus Inonotus belongs to the Hymenochaetaceae, a family characterised by rusty brown, fibrous flesh that darkens in alkali, and by the absence of a hard lacquered crust. Unlike the perennial hoof fungi of the same family, Inonotus species build a fresh soft fruit body each year rather than adding tube layers to an existing one.

Ecologically the species is a parasite of living trees, entering through wounds and pruning cuts and hollowing the heartwood over many years. Its strong association with ash, apple and walnut makes it a familiar sight in orchards, hedgerow trees and street plantings across Europe, and it occurs widely in Asia and North America as well.

Fruit body

The bracket is 8 to 30 cm wide and can be 10 cm or more thick at the point of attachment, semicircular to broadly cushion-shaped, and attached along a broad base directly to the bark. It is normally solitary or in a short vertical series, and unusually heavy and water-laden when fresh.

Upper surface

The upper surface is densely covered with coarse, matted, stiff hairs, giving a shaggy or hispid texture that can be felt as well as seen. Fresh growth is bright rusty orange to tawny or yellow-brown; with age it darkens through deep red-brown to dark brown and finally almost black, and the hairs mat down or wear away so that old brackets become dark, crusted and rather formless.

Pores

The pore surface is pale yellow to whitish-cream or greyish-yellow when young, staining and ageing rusty brown wherever it is touched or bruised. Pores are round to slightly angular, about 2 to 3 per millimetre, and the tubes are 1 to 4 cm deep in a thick bracket. Droplets of clear to amber liquid often stand on the pore surface and margin of an actively growing specimen.

Flesh and spore print

The flesh is thick, soft, spongy and juicy when fresh, bright rusty orange to yellow-brown, faintly zoned, and made of coarse radiating fibres. As the bracket ages the flesh becomes fibrous-corky and then light, hard and brittle when dry. The spore deposit is yellowish-brown.

This bracket grows on living broadleaved trees, fruiting from wounds, branch stubs, pruning scars and old cankers, usually well up the trunk or on a major limb rather than at the base. In Europe the strongest associations are with ash and apple, and it is also frequent on walnut, plane, mulberry, elm and various other broadleaves; in North America it is recorded from ash, apple, oak and hickory among others.

Fruiting begins in late summer, peaks in autumn, and the blackened dead brackets remain attached through winter and sometimes into the following year. The species is common across Europe including orchards, parks, hedgerows and street tree plantings, and it is broadly distributed through temperate Asia and much of North America. Because it recurs from the same infection point, brackets often appear year after year on the same tree at the same height.

Inonotus hispidus is a parasite that causes a white rot of the heartwood and inner wood of living trees. Colonisation begins where injury exposes the wood, and the mycelium then spreads slowly upward and downward within the trunk, degrading lignin and cellulose so that the affected wood becomes pale, soft and eventually hollow. Trees can carry the infection for many years while continuing to grow.

Once the tree dies the fungus continues as a saprotroph in the standing or fallen remains. Hollowing of living trunks by this and similar decay fungi is an important ecological process, creating cavities that are used by roosting bats, hole-nesting birds and invertebrates, and generating the wood-mould that specialist saproxylic beetles depend on. The annual fruit bodies release enormous quantities of yellowish-brown spores in autumn, and their collapse and decay in turn feeds a small community of fungus-feeding flies and beetles.

Pseudoinonotus dryadeus, the Weeping Polypore, has the same rusty fibrous flesh but grows at the base of oaks rather than high on ash, has a lumpy, warted, only finely velvety upper surface rather than a shaggy one, and exudes conspicuous amber droplets from the top of the bracket. Inonotus cuticularis is thinner, more fan-shaped, often grows in overlapping tiers on beech, and has a finer, less matted hair covering.

Phaeolus schweinitzii has a velvety rather than shaggy top and greenish-yellow pores, and grows at the base of conifers. Laetiporus species form tiered fans that are bright orange above and sulphur-yellow below, with smooth hairless upper surfaces and soft white flesh, quite unlike the rusty fibrous flesh here. Any doubt is resolved by cutting the bracket: the rusty brown, coarsely fibrous, zoned context of Inonotus is unmistakable.