Cinnabar Polypore

Few wood-decay fungi are as easy to spot as the Cinnabar Polypore. The whole fruit body — upper surface, pore layer and internal flesh — is saturated with a bright cinnabar to vermilion pigment, so a single small bracket stands out against grey deadwood from many metres away. The pigment is a family of compounds related to cinnabarin, and it persists, though fading toward salmon or brick, long after the fruit body has dried.

The species belongs to Pycnoporus, a small genus closely allied to Trametes and often folded into it as Trametes cinnabarina. Like its relatives it is a tough, stalkless, broadly attached bracket with a white-rot habit, but it lacks their concentric zoning: the upper surface is essentially plain, wrinkling and fading with age rather than banding.

It is a fungus of well-lit, exposed deadwood — wind-broken branches, hedgerow snags, storm debris — and is widely distributed across the temperate northern hemisphere.

Cap

Brackets are 2-10 cm across and 0.5-2 cm thick, semicircular to fan-shaped or shelf-like, broadly attached and stalkless, sometimes fused in small groups. The upper surface is bright cinnabar-red to orange-red when fresh, becoming wrinkled, roughened and faded to pale orange, salmon or brick with age and exposure. It is finely velvety at first and soon smooth, and it lacks the strong concentric zoning of most Trametes species, though faint furrows may develop.

Pores

The pore surface matches or exceeds the cap in intensity, a deep red-orange, and is one of the most vivid pore layers of any temperate bracket. Pores are round to slightly angular at about 2-4 per millimetre, with a tube layer 1-6 mm deep, also coloured red-orange in section.

Flesh & spore print

The context is orange to reddish throughout, tough, corky to leathery, and 1-10 mm thick — cutting a bracket in half to show the coloured interior is a reliable confirmation. The spore print is white, which contrasts sharply with the fruit body colour and is a genus-level character.

It fruits on dead hardwood, favouring recently dead, well-lit branches and small trunks. Cherry and other Prunus, birch, oak, beech, hazel, ash and willow are among the frequent hosts. Wind-snapped limbs still attached to the tree, hedgerow snags and exposed storm debris are typical sites; it is much less often found on shaded, ground-level logs. Conifer wood is used only rarely.

The species is widespread across Europe, temperate Asia and North America. New brackets appear mainly from summer into autumn, but the tough coloured fruit bodies persist through winter, gradually fading to a pale salmon or dull brick shade.

The Cinnabar Polypore is a saprotroph that causes a white rot, degrading lignin as well as cellulose and leaving the affected wood pale, soft and fibrous. It is a pioneer coloniser, typically arriving on wood that has died within the last season, and its preference for exposed sunlit branches suggests good tolerance of drying and ultraviolet exposure — the strong pigment may contribute to that tolerance.

In the deadwood succession it holds the substrate for a year or two before being displaced by later-stage decomposers. Its persistent brackets remain conspicuous through winter and provide shelter for small invertebrates, while the softened branch wood it leaves behind is readily worked by beetle larvae.

Pycnoporus sanguineus is the closest match, a thinner, more flexible relative of warmer regions with a thinner context and smaller pores; ranges overlap only marginally in subtropical zones. Trametes versicolor forms with rusty-orange bands are separated instantly by their white pore surface and white context, and by their strong concentric zoning.

Stereum species can carry orange tones above but have a smooth, poreless underside. Hapalopilus species are duller pinkish-brown, softer, and lack the vivid red-orange pore layer. Fresh Fomitopsis pinicola has a red-orange band on its margin but is a thick woody hoof with a white to cream pore surface and a resinous crust above.