Summary:
Features include 1) growth on barkless, decayed logs of Western Red-cedar, 2) a pulvinate to crustose fruitbody that is rosy when fresh, smooth to slightly undulating, dull, pruinose or shiny where polished, in sections minutely layered, in layer specimens the margin abrupt, 3) spores that are elliptic to cylindric, smooth, and inamyloid, 4) rather large basidia, 5) a monomitic hyphal system, the hyphae ascending through scattered basidial zones, with clamp connections, and 6) crystals forming when sections are placed in hot cotton blue - lactic acid. The crystals form when microscopic sections are heated but not boiled in a drop of cotton-blue - lactic acid, crystal formation beginning from 30-120 seconds after heating and attaining maximum size in 10-15 minutes, the crystals basically circular, 15-20 microns in diameter when mature, each composed of a series of fan-shaped segments that grow radially, (Ginns(14)).

Microscopic:
SPORES 6.8-7.6(9.2) x 3.4-4.0(4.4) microns, elliptic to subcylindric, adaxially flattened or slightly concave, smooth, inamyloid, acyanophilic, colorless, thin-walled; BASIDIA 4-spored, clavate to distinctly pedicellate, 34-40 x 7-9.6 microns, acyanophilic; HYPHAE monomitic, 2-4.6 microns wide, "ascending, no horizontal layer next to substrate, scattered through thickened hymenial zones, branched, somewhat woven", the walls colorless, typically 0.6-0.8 microns thick or thin, inamyloid, acyanophilic, with single clamp connections; "strata are primarily composed of collapsed basidia and the detail is difficult to determine", (Ginns(14))

Notes:
Thujacorticium mirabile is known from the type specimen found in BC, (Ginns(5)).

Synonyms and Alternate Names:
Aleurodiscus minnsiae H.S. Jacks.
Laeticorticium minnsiae (H.S. Jacks.) Donk