Stereum - click to expand

The orange colouration rescues these from obscurity, as does the fact that they usually project away from the surface and are not often fully resupinate. When scratched, they may stain/bleed red or yellow. The species are best separated microscopically, but can often be reliably identified by comparing how much they attach to the wood (single point, versus a line versus mostly resupinate), how bright or dull the orange colouration is on the underneath and whether or not it stains/bleeds yellow, red or neither when scratched.

Species mentioned: Stereum hirsutum, complicatum, ochraceoflavum, gausapatum, rugosum, subtomentosum, ostrea, sanguinolentum, atrorubrum

 

Stereum hirsutum - Most collections of Stereum are called this, because this species is the only one that most people know. It certainly is abundant, but many collections do end up being other species. It is mostly projecting from the wood, but broadly attached. The underside is bright orange, and the fruitbody is usually 1-2 mm thick. Like most, it is a hardwood species.

Western North American collections differ consistently from European sequences by the same single bp difference in ITS1 and the same 3 bp differences in ITS2 plus a large insertion of 8 bp. There may also be a few extra single indels. There is definitely some geographic isolation happening but I don't know that it's enough to consider ours a different species in need of a new name.

Stereum hirsutum © Julie Jones

 

Stereum complicatum - Thinner than S. hirsutum (<0.5 mm), also brightly coloured and usually more wrinkled or complicated looking. It is probably common. We need local and European sequences to see if we have the real thing. We have eastern NA sequences that appear to be this species.

probable Stereum complicatum © James Hilliard

 

Stereum ochraceoflavum - A hairy capped species with a fringed edge, dull colours underneath and reportedly found on small pieces of wood. No DNA data yet to see if we really have this eastern NA species described from PN and FL.

probable Stereum ochraceoflavum © Daniel Winkler

 

Staining red when scratched ("red bleeders")

Stereum cf gausapatum - Usually capped, only on oak, bright orange, bleeding red when scratched. Stereum hirsutum can be on oak, but won't always be, and is also bright orange, but doesn't stain red. Our Vancouver Island and WA sequences matches sequences from eastern North America (with a handful of alleles or dirty sections being the only differences), but we don't have European sequences yet of this EU mushroom to see if our species is the real thing or a sister species.

Stereum cf rugosum - Pale ochre to pinkish-brownish instead of bright orange. Also a resupinate red bleeder on various hardwoods, rumoured to occur here. We need local collections to compare to European sequences to verify these reports.

Stereum sanguinolentum - A similar looking resupinate red bleeder, but dull tan-orange coloured on conifers. PNW and Eastern North American sequences match European sequences, so it is the same species worldwide.

 

probable Stereum gausapatum, rugosum and sanguinolentum © A and O Ceska

 

Stereum subtomentosum - Mostly a cap, attached to the wood at a single point only, dull orange underneath, staining yellow-orange when scratched. On hardwoods.

Stereum ostrea - identical, but bleeding red or yellow turning red. So far, sequences of this rarely reported species have all turned out to be other species, according to a recent study, so we need sequences of supposed collections to test the theory that all of ours are really just Stereum subtomentosum that happens to stain more towards the orange-red end of the spectrum instead of yellow.

Stereum subtomentosum © Danny Miller

 

Stereum atrorubrum  - described from BC but only known from the 1890 type, so we really don't know what it is. I'm curious.

Aleurodiscus and Xylobolus - click to expand

TBD