Inonotus hispidus (Bull.) P. Karst. - Shaggy Bracket

Phylum: Basidiomycota - Class: Agaricomycetes - Order: Polyporales - Family: Hymenochaetaceae

Distribution - Taxonomic History - Etymology - Identification - Reference Sources

The hairy upper surface of this massive bracket distinguishes it readily from Beefsteak Fungus. Inonotus hispidus is quite rare; it occurs mainly on trunks of broad-leaved trees, and in particular Fraxinus (ash trees) and Mallus (apple trees).

White rot results from attack by the Shaggy Bracket, and infected trees have to be felled because this aggressive decay agent weakens the timber and can result in trunks or branches breaking and falling in stormy weather.

The bracket on the left above is younger that the one below. It appeared in 2012 on an old apple tree in a small orchard in Worcestershire. (The upper photograph was taken by Jim Norris and is shown here with his kind permission.) The Shaggy Bracket fungi above were found growing on an apple tree in Chamborigaud, in southern France, during October 2012.

This annual bracket fungus appears in mid to late summer, and the fruitbodies expand, darken, developing a thinner rounded edge before blackening. The brackets decay and will usually have fallen off their host trees by late autumn.

Distribution

Widespread and fairly common in England, the Shaggy Bracket seems to be much less common in Ireland, Wales and Scotland. On mainland Europe Inonotus hispidus is very common in central and southern countries but less so in the colder north.

Young fruitbodies sometimes exude clear or slightly reddish liquid droplets, as illustrated by the specimens of the left. These young Shaggy Brackets were seen together with more mature brackets on an old Ash tree in Bedfordshire, England. Photograph: Matt Leivers, by whose kind permission this picture is shown here.

This colourful but inedible bracket fungus is also found in many other parts of the world including much of Asia and North America. In the USA it is sometimes referred to by the common name Inonotus Canker.

Taxonomic history

In 1785 French mycologist Jean Baptiste Francois Pierre Bulliard (1742 - 1793) described this species and named it Boletus hispidus. This polypore was given its current scientific name in 1879 by the Finnish mycologist Petter Adolf Karsten (1834-1917).

Synonyms of Inonotus hispidus include Inonotus hirsutus and Polyporus hispidus (Bull.) Fr.

Etymology

Inonotus, the genus name of the Shaggy Bracket fungus, comes from ino- a prefix meaning fibrous, and ot which means an ear. The specific name hispidus comes from Latin and means stiffly hairy, shaggy or spiny.

Identification guide

	The old Inonotus hispidus fruitbody shown on the left is growing on the trunk of a dying apple tree. The Shaggy Bracket is a tough, inedible fungus and quite rare in most parts of the British Isles other than in major fruit-growing areas.
	Caps When young, the cap of a Shaggy Bracket - the specimens shown on the left was growing on an old apple tree (picture kindly contributed by Peter Dyment) - is a rusty reddish yellow on its upper surface and has a broad, rounded margin that becomes much narrow and sharper as the fruitbody matures. Up to 30cm across when fully developed, the rust-brown brackets of Inonotus hispidus have concentric zoning on a distinctive, downy upper surface that is usually wrinkled at the edges. Inside the bracket the flesh is pale creamy brown and dries very hard. Brackets are stemless and broadly attached to the substrate.
	Tubes The tubes, spaced at 2 or 3 per mm, are 6 to 10mm deep on a typical bracket, but I have seen tubes up to 18mm deep on very large fruitbodies of Inonotus hispidus.
	Pores The pores of the Shaggy Bracket are initially cream, but they soon turn buff and eventually brown as the fruitbody begins to decay.
	Spores Broadly ellipsoidal, smooth, 7-10 × 6-8µm; inamyloid. Spore print White.
Odour/taste	Not distinctive.
Habitat & Ecological role	Inonotus hispidus, the Shaggy Bracket, is saprobic and appears on dead or dying broad-leaf trees, notably ash and apple but also occasionally on poplar, beech, oak and sycamore.
Season	Late summer to winter.
Similar species	Fistulina hepatica, the Beefsteak Fungus, produces softer fruitbodies that ooze red juice when cut.

Above: Looking like a ripe peach, this very young Shaggy Bracket seems quite incongruous on an apple tree - central France, October 2012.

Reference Sources

Mattheck, C., and Weber, K. Manual of Wood Decays in Trees. Arboricultural Association 2003.

Fascinated by Fungi, 2nd Edition, Pat O'Reilly 2016, reprinted by Coch-y-bonddu Books in 2022.

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi.

Acknowledgements

This page includes pictures kindly contributed by Jim Norris.

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