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

Summary:
Features include 1) resupinate growth on wood, 2) a fruitbody that is arachnoid to hypochnoid, colored cream to pale buff, 3) spores measuring 7-10 x 2.5-5 microns that are navicular to elliptic with a prominent apiculus, smooth, inamyloid, and colorless, 4) 4-8-spored basidia, and 5) wide subicular hyphae with right angle branching and without clamp connections. Note that Corticium vagum (Berk. & Curt.) sensu Burt is a synonym of Rhizoctonia solani.

Botryobasidium vagum has been found in BC, WA, OR, ID, AB, MB, NB, NS, FL, GA, IA, IL, KS, LA, MA, MD, MI, MN, MO, NC, NJ, NM, NY, OH, PA, RI, SC, SD, TN, TX, and WI, (Ginns). Distribution includes AZ (Gilbertson).

Fruiting body:
arachnoid to hypochnoid; cream to pale buff, (Gilbertson), cream to pale buff (Martin), 0.02cm thick, "reticulate, hypochnoid, then continuous and subpellicular, often extensively confluent, loosely interwoven"; grayish white, greenish gray, yellowish gray, dull yellow, grayish yellow, grayish beige, or even brownish gray, (Jung, H.S.(1)), resupinate, arachnoid to hypochnoid, cream to light buff, margin thinning out, (Lindsey), spore deposit white (Buczacki)

Microscopic:
SPORES 7-10 x 3.5-5 microns, navicular [boat-shaped] to elliptic, tapered at apex, curved or flattened on one side, smooth, inamyloid, colorless, with prominent apiculus; BASIDIA 4-8-spored, 7-9 microns wide, cylindric, often inflated at base or apex; CYSTIDIA absent; SUBICULAR HYPHAE up to 10 microns wide, branching at right angles, thin-walled, without clamp connections, (Gilbertson), SPORES 8-9 x 2.5-3 microns, elliptic, CYSTIDIA absent; hyphae without clamp connections, (Martin), SPORES 7.2-12(13.6) x 3-5 microns, narrowly navicular, obliquely subfusiform, or navicularly subcylindric; BASIDIA 6-spored, (13.6)16-24.8 x (7.2)8.8-12.8 microns, short clavate, then subcylindric, somewhat constricted in the middle; HYPHAE septate, without clamp connections, subhymenial hyphae 5.6-8 microns wide, colorless, thin-walled or slightly thick-walled (wall up to 1 micron thick), densely branched into candelabra, basal hyphae 8-12.4 microns wide, yellowish, thick-walled (wall up to 2.4 microns thick), commonly branched, (Jung, H.S.), SPORES 7-10 x 3.5-5 microns, navicular to elliptic, "tapered at the apex, curved or flattened on one side, with a prominent apiculus", colorless, inamyloid; BASIDIA 4-8-spored, 18-30 x 7-8 microns, simple septate at base; CYSTIDIA and other sterile elements lacking; HYPHAE monomitic, subicular hyphae up to 10 microns wide, thin-walled, simple-septate, branching at right angles, (Lindsey)