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

Summary:
Features include 1) resupinate growth on wood, 2) the soft membranous consistency of a cream colored pellicular layer, sometimes with an olive tint, a brownish cobwebby subiculum, and brownish rhizomorphs, 3) spores that are elliptic, smooth, inamyloid, and colorless, 4) a monomitic hyphal system, the hyphae with clamp connections, and some hyphae encrusted.

Leptosporomyces fuscostratus has been found in BC, OR, ID, NS, ON, PQ, AZ, CO, CT, FL, IL, MA, MD, MI, MN, MO, NH, NM, NY, PA, and WI, (Ginns). It has also been found in Austria, Czechoslovakia, France, Italy, Portugal, Sweden, United Kingdom, Turkey, and the USSR, (Julich).

Fruiting body:
thin, pellicular; whitish or pale cream; when dry more or less cracked; easily separable, with loose subiculum, "light brownish rhizomorphs in subiculum and periphery", (Eriksson), resupinate, forming thin membranous patches several centimeters across, attached loosely, consistency membranous, soft; "cream-colored, sometimes with an olive tint"; smooth; margin fringed; subiculum brownish, with rhizomorphs, (Breitenbach), resupinate, effused, soft, easily separated; spore-bearing layer a thin, compact pellicle; "light buff" to "ivory yellow" ("cinnamon buff" to "clay color"); cracking on drying to expose the pale brownish to pale buff, arachnoid [cobwebby] subiculum; "margin thinning out, usually with fine cream-colored rhizomorphs", (Gilbertson), 3-6cm x 2-3cm x 0.01-0.03cm, forming a thin, fragile, cartridge-buff to pale smoke-gray pellicle on an arachnoid [cobwebby] or fibrillose, wood-brown subiculum, the spore-bearing surface cracking into small polygonal masses about 0.1cm in diameter, the margin colored as the substance, fringed, (Burt), spore deposit white (Buczacki)

Microscopic:
SPORES about 4 x 2 microns, narrowly elliptic to subcylindric, inamyloid, colorless, thin-walled; BASIDIA 10-15 x 3-4.5 microns, narrowly clavate, normally 4-spored; HYPHAE monomitic, 2-4 microns wide, thin-walled or slightly thick-walled, more or less encrusted, anastomoses especially in the rhizomorphs, somewhat nodulose in subhymenial area on old specimens, otherwise even, light brown in rhizomorphs and basally, otherwise colorless, clamp connections at all septa, (Eriksson), SPORES 3.5-4.5 x 2-2.4 microns, elliptic, smooth, inamyloid, colorless; BASIDIA 4-spored, 10-15 x 3-4.5 microns, clavate, with basal clamp connection; CYSTIDIA absent; HYPHAE monomitic: subhymenial hyphae 1.5-3.5 microns wide, thin-walled, with clamp connections, colorless, some sparsely encrusted; subicular hyphae 2-5 microns, thin-walled to thick-walled, with clamp connections, brownish, some encrusted, (Breitenbach), SPORES 3-4 x 2-2.5 microns, elliptic to short cylindric, flattened on one side, smooth, inamyloid, colorless; BASIDIA 4-spored, 10-12 x 4-4.5 microns, clavate; CYSTIDIA none, HYPHAE monomitic, subicular hyphae with abundant clamp connections, subhymenial hyphae 2-3 microns wide, "loosely arranged, with frequent branching", colorless, colorless to pale yellowish in KOH, thin-walled, basal hyphae 3-5 microns, light brown in KOH, walls thin to moderately thickened, "some lightly to heavily incrusted with a fine, pale brownish crystalline material", (Gilbertson), SPORES 3-4 x 2 microns, flattened on one side, colorless; hyphae 2.5 microns wide, pale brownish, nodose-septate [septa with clamp connections], sometimes encrusted, (Burt)