Summary:
Features include flat growth on conifer wood with the pore surface exposed, a soft light consistency, yellow-brown pores and margin, easy separability from wood, and microscopic characters including the absence of setae. The description is derived from Gilbertson(1).

Microscopic:
spores 6-8.5 x 4.5-5.5 microns, broadly elliptic to oval, smooth, inamyloid, colorless; basidia 4-spored, 14-20 x 6-8 microns, clavate, simple-septate at base; setae and other sterile hymenial elements absent; context hyphae "reddish brown to pale yellowish-brown in KOH, thin-walled, rarely to frequently branched, simple-septate, 4-9 microns in diam, also some thick-walled hyphae, often with light, scattered incrustation, tramal hyphae similar"

Notes:
Inonotopsis subiculosa has been found in BC, AB, NB, NS, ON, CO, MI, MT, NY, and WI, (Gilbertson). It is known from 2 collections on Douglas-fir at Prince George (Ginns(28)).

Synonyms and Alternate Names:
Helvella nigrella (Seaver) F.L. Tai
Plectania nannfeldtii Korf