E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
{See also Stereum Table.} Features include 1) growth on hardwoods, often growing together to form a row or rows on twigs and small branches, when young sometimes suspended from the midpoint of a circular cap surface, also resupinate on undersides of the wood, 2) a small, somewhat tough, but relatively thin and pliant fruitbody, the upper side finely hairy-tomentose with hairs pointing toward the margin, indistinctly zoned, whitish or grayish to ocher, with a fringed margin, 3) a spore-bearing surface that is ocherish, smooth, and undulating-tuberculate, 4) spores that are cylindric to elliptic, smooth, amyloid, and colorless, 5) acute tipped hyphidia and also pseudocystidia (but not pseudoacanthohyphidia or conducting hyphae), 6) hyphae of 2 types: a) thin-walled to thick-walled, septa without clamp connections, and b) thick-walled. |Stereum complicatum, Stereum gausapatum, Stereum hirsutum, and Stereum ochraceoflavum are members of the subgenus Stereum, having sharp tipped hyphidia but lacking the pseudoacanthohyphidia found in subgenus Aculeatostereum. |In Stereum ochraceoflavum, the well defined cutis present in most Stereum species is lacking, and the tomentum is derived directly from the pale colored context. (This well defined cutis layer is lacking also in Stereum striatum [found in eastern North America and growing on Carpinus or rarely Nyssa], but the tomentum is more or less appressed in that species, giving a cap surface that appears lineate-striate, shining, and silky). (Chamuris).

Stereum ochraceoflavum has been found in BC, WA, NF, NS, ON, AL, AR, AZ, CA, CO, CT, DE, FL, GA, IA, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, NH, NJ, NY, OH, PA, SC, TN, TX, VA, VT, and WI, (Ginns). It has also been found in Europe including Switzerland, Africa, and Asia, (Breitenbach).

Fruiting body:
semicapped, caps up to 1cm across and extending up to 0.5cm from the substrate, 0.02-0.04cm thick, usually concrescent to form rows and resupinate on the underside of the substrate, consistency somewhat tough, elastic; young caps often cyphelloid, "upper surface finely hirsute-tomentose, indistinctly zoned", hairs gray-whitish to ocher-whitish, sometimes colored greenish by algae, cap margin sharp-edged, fringed; spore-bearing surface brown-ocher to gray-ocher, "smooth, undulating-tuberculate and commonly somewhat umbonate at the place of attachment", (Breitenbach), cup-shaped [spore-bearing surface facing downward] or effused-reflexed, cap surface whitish to gray, more rarely with ochraceous or brownish tinge, hairs loose, silky-hirsute, predominantly pointing toward the margin; spore-bearing surface cream-buff to pale orange-yellow, (Julich)

Microscopic:
SPORES 7-9 x 2-3 microns, cylindric to elliptic, smooth, amyloid, colorless; BASIDIA 4-spored, 30-37 x 6-7 microns, narrowly clavate, without basal clamp connection; PSEUDOCYSTIDIA 80-110 x 5-7 microns, thick-walled, emerging from the skeletal hyphae, without contents; CYSTIDIOLES 30-35 x 3-4.5 microns [by illustration acute-tipped hyphidia]; HYPHAE dimitic, generative hyphae 2-4.5 microns wide, thin-walled to thick-walled, septa without clamp connections, skeletal hyphae 5-7 microns wide, thick-walled, (Breitenbach), SPORES 5.5-9 x 1.5-2.5 microns, cylindric; BASIDIA about 27 x 4.5-5 microns, generative HYPHAE 1.5-4 microns wide, skeletal hyphae 4-7 microns wide, (Julich)