What You Should Know
Cerrena unicolor is a basidiomycete fungus in the Polyporaceae family with a white rot on the surface of hardwoods and is globally distributed.
The mushroom may be sessile, effused-reflexed, or rarely almost entirely resupinate on horizontal surfaces. If cut or torn, a thin black zone (appearing as a line) separates the flesh of the cap from the surface.
Cerrena unicolor spores get into the ovipositor of the wood-boring wasp (the horntail) when she drills into hardwood logs (often logs of beech). The spores get carried around with the wasp's eggs, and wind up germinating when eggs are laid; mycelium grows quickly and serves as the food source for larvae.
The green coloration on this fungus is not produced by the fungus itself, but rather, is due to algal growth. Cerrena unicolor is also called Daedelea unicolor by some mycologists.
Other names: Mossy Maze Polypore.
Cerrena unicolor Mushroom Identification
Saprobic on the deadwood of hardwoods (very rarely reported on conifers); causing a white rot; annual; growing in overlapping clusters; found year-round; widely distributed in North America but rare or absent in the Southwest.
Sometimes lacking a cap (especially when growing on the undersides of logs), appearing like a pore surface that lost its mushroom, but more commonly with a kidney-shaped to fan-shaped cap 3-10 cm across; upper surface velvety to hairy, whitish to brownish but often appearing green from algae; usually with concentric zones of texture and/or color.
Whitish when young, becoming gray; pores maze-like or slot-like, becoming tooth-like with age; tubes to 4 mm deep.
Whitish; with a dark line just beneath the cap surface; leathery.
Spore Print: White.
Cerrena unicolor Taxonomy and Etymology
Cerrena unicolor was described scientifically in 1785 by French mycologist Jean Baptiste Francois Pierre Bulliard, who created its basionym when he gave it the scientific binomial name Boletus unicolor. It was American mycologist William Alphonso Murrill (1869 - 1957) who in 1903 transferred this species to the genus Cerrena and established its widely-accepted scientific name as Cerrena unicolor.
The many synonyms of Cerrena unicolor include Boletus unicolor Bull., Agaricus cinereus (Pers.) E. H. L. Krause, Antrodia incana (P. Karst.) P. Karst., Polyporus latissimus Fr., Sistotrema cinereum Pers., Cerrena cinerea (Pers.) Gray, Coriolus unicolor (Bull.) Pat., and Trametes unicolor (Bull.) PilÃ¡t.
The specific epithet unicolor comes from Latin and means 'of one color'.
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