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.
Stereum hirsutum
Most collections of Stereum are called this,
because this abundant species
is the only one that most people know. 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 common 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
Stereum cf gausapatum
Mostly resupinate on oak, bright orange, bleeding red when scratched.
Rare here. Our
Vancouver Island sequence 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 to see if our species is the real thing.
Stereum cf rugosum
Pale brownish instead of bright orange. Also a
resupinate
red bleeder on various hardwoods, rumoured to occur here
rarely. We need local
collections to compare to European sequences to verify these reports.
Stereum cf sanguinolentum
A
common, similar looking resupinate red bleeder,
but dull tan-orange coloured on conifers. Eastern North American sequences
match European sequences. We need local sequences to verify that ours is the
same species too, but it probably is.
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.
Uncommon 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.
