Smoky Bracket Identification Guide

The First Impression

Smoky Bracket is a fungus of dead hardwood in almost any wood, park or hedgerow, and once you have the search image it turns up constantly. The typical find is a fallen beech, birch or ash trunk, a stump left from a felling, or a standing dead limb, with a long row of thin, wavy-edged brackets running along it. From above they read as pale grey-buff shelves, often overlapping in tiers or fusing sideways into a continuous ruffled band a metre long.

The giveaway is the underside. Tilt your head, or lift a bracket edge with a finger, and the pore surface is a distinct smoky grey - sometimes ash grey, sometimes almost bluish or nearly black in older material - with a narrow whitish rim along the growing margin. That grey-under, pale-over contrast is the essence of the species, and it can be read from a couple of paces once you know to look for it.

A second common form is largely flat. Where the fungus grows on the underside of a log or on a vertical face it spreads as a resupinate crust with only a small turned-out shelf at the top edge, so you may find long grey sheets with a fringe of little caps along one side. Both forms are the same fungus.

Reading the Cap Surface

Individual caps are small: 2 to 6 cm out from the wood, sometimes wider where several fuse, and remarkably thin, usually only 1 to 5 mm thick. The outline is a fan, a semicircle or an irregular wavy shelf, and the margin is thin, sharp and often lobed or crinkled.

When young, the upper surface is finely velvety or minutely hairy and coloured whitish, cream, pale grey or buff, frequently with faint concentric zoning that shows as slightly different shades rather than sharp bands. With age it loses the fuzz, becomes smoother, and darkens through greyish-brown to a dirty ochre-brown, sometimes with a greenish cast where algae colonise the older parts. Old, weathered specimens turn dark and can look almost black at the base of the shelf.

Run a finger along the margin. Fresh brackets have a pale, almost white growing edge, which contrasts with both the darker cap behind it and the grey pores below.

The Pore Surface

This is the diagnostic surface, and it deserves a lens. The colour when fresh is smoke grey to lead grey, occasionally with a faint bluish or violaceous tinge, deepening to near black in old or bruised material. Handling darkens it further, so specimens carried loose in a pocket often come out looking much blacker than they did on the log.

The pores themselves are minute. Expect roughly 4 to 7 per millimetre - fine enough that the surface looks smooth and matte to the naked eye and only resolves into round to slightly angular mouths under magnification. If you can easily count individual pores without a lens, you are looking at something else.

The tube layer is shallow, generally 0.5 to 2 mm deep, and grey throughout.

The Cross-Section and the Black Line

Cut a bracket in half vertically with a sharp knife, from the growing margin back to the attachment. The section shows three things. First, the flesh above the tubes is thin, tough and pale - whitish to pale buff or cream, and usually 1 to 3 mm at most. Second, the tube layer below it is distinctly darker grey. Third, and decisively, a narrow dark to black line separates the pale flesh from the grey tubes.

That black line is the single best confirmation of the genus Bjerkandera in the field. It is thin, sometimes needing a lens and a clean cut to see properly, and it is best observed on a fresh, well-hydrated specimen. Look at the cut edge in good light, ideally with the section held against a pale background.

The texture of the whole bracket is tough and slightly leathery when fresh, drying hard, brittle and papery. There is no gelatinous layer, no soft watery flesh and no colour change beyond the general darkening on handling.

Taking a Spore Print

Bracket fungi are awkward to print, but the method is simple. Cut a section of bracket carrying an intact pore surface, and support it pore-side down over dark paper or a dark tile with matchsticks or a wire loop so that air can circulate underneath. Cover it with a container to hold humidity and leave it overnight in a cool place.

The deposit is white. Since the pore surface is grey and the flesh pale, a white print is not obvious against pale paper, which is why a dark surface is essential. A white spore deposit combined with grey pores and the black line confirms Bjerkandera and separates it from genera with brownish deposits.

Substrate, Season and Ecology

Smoky Bracket is a saprotroph of dead hardwood and one of the most widespread wood-rotting polypores in temperate forests. It fruits on fallen trunks, large branches, stumps, standing dead limbs, cut log stacks and worked timber left outdoors. Beech, birch, ash, oak, willow, poplar and fruit trees are all regular hosts, and it occasionally appears on conifer wood, though that is much less usual. It also colonises damaged wood on living trees.

It causes a white rot, degrading lignin and leaving the residual wood pale, soft and fibrous, and it is an important early-to-middle stage decomposer in the breakdown of fallen hardwood. Colonies persist on a single log for years, with new brackets forming along the margins of old ones.

Fruit bodies are annual but tough enough to survive well into the following season, so weathered blackened remnants can be found at any time of year. Fresh growth with the pale margin and clean grey pores is commonest from late summer through autumn, and again during mild damp spells in winter and spring.

Separating It from the Look-alikes

Bjerkandera fumosa is the closest relative and shares the black line in section. It is a bigger, thicker, more substantial bracket, its pore surface is a paler greyish-buff, greyish-brown or smoky cream rather than dark smoke grey, its pores are slightly larger, and it favours ash and willow. Many collections also carry a faint aniseed-like smell.

Trametes species overlap in size and habit. Trametes versicolor is thinner, more strongly and colourfully zoned above, and crucially has a whitish to cream pore surface. Trametes hirsuta is coarsely hairy above with white to greyish-cream pores that never reach smoke grey, and it lacks the black line entirely.

Cerrena unicolor can look strikingly similar from above and also has a dark line in section, but its underside is not a neat fine-pored surface: it breaks up into maze-like slots and then into flattened teeth as it matures, and its cap is usually hairy with a distinct green algal film.

Datronia mollis has larger, angular, brownish pores and a more resupinate habit with a narrow dark cap edge.

Schizopora and Hyphodontia crusts on the same logs are entirely flat, cream to buff, and often split into jagged teeth without any bracket at all.

Finally, do not confuse an old weathered Trametes with a fresh Bjerkandera. Weathered white-pored brackets go grey and dirty with age. The test is the cut: a genuine Bjerkandera has grey tubes and a black line even in fresh, clean tissue, while a dirty Trametes is pale all the way through.

A Working Sequence

Dead hardwood, thin wavy tiered shelves, pale hairy grey-buff top, smoke-grey minutely pored underside with a white growing edge, tough thin flesh, black line between flesh and tubes in section, white print. Cut one bracket in half and the identification takes about ten seconds.