Polyporus melanopus

Description

Polyporus melanopus is an inedible species of mushroom in the genus Polyporus. It has a brown velvety cap that grows up to 10 cm across. It is centrally depressed and has tough flesh. The stem has a soft black felt covering. It can be found growing on dead wood, or from a submerged sclerotium, from spring through fall.

Polyporus melanopus has been found in BC, WA, OR, ID, AB, MB, NS, ON, PQ, YT, AK, AL, AR, AZ, CA, CO, CT, DE, GA, IA, KY, MA, ME, MI, MN, MT, NC, ND, NE, NH, NJ, NY, OH, PA, TN, UT, VA, VT, WI, WV, and WY, (Gilbertson), and Europe, Asia, and Australia, (Breitenbach).

Mushroom Identification

1. Cap

   Up to 10 cm across and 5cm thick, circular; reddish-brown to smoky blackish brown, not zoned; "smooth, finely scurfy"; margin often wavy or turned up.

2. Flesh

   Up to 0.5cm thick, firm, rather friable when dry, not zoned; white, (Gilbertson), about 0.1cm thick, white to cream, (Phillips), 0.1-0.2cm thick, corky, tough; white, (Breitenbach)

3. Pores

   6-8 per mm, circular to angular, thick-walled; whitish; tube layer up to 0.05cm, slightly darker than flesh, distinct from it and separated by a faint brownish layer, (Gilbertson), 4-7 per mm, circular, decurrent in specimens with lateral stem; whitish to cream then pale straw-colored; tube layer up to 0.3cm thick, cream to straw-colored, (Phillips), 3-4 per mm, irregularly rounded, sometimes decurrent onto one side of the stem; white, cream to brownish; tube layer 0.1-0.2cm thick, (Breitenbach)

4. Stem

   Up to 11cm x 2cm, central, underground part root-like; blackish in the upper part, dark brownish-black in the lower part; velvety in the upper part, bald in the lower part.

5. Odor and Taste

   The pleasant odor and mild taste (Breitenbach).

6. Microscopic

   Spores 7-9 x 3-3.5 microns, cylindric, smooth, inamyloid, colorless; basidia 4-spored, 18-28 x 6-8 microns, clavate, with basal clamp; cystidia none, cystidioles present, 16-21 x 4-5 microns, fusoid, with basal clamp; hyphae dimitic, generative hyphae of context 3-5 microns wide, colorless in KOH, thin-walled, with clamp connections, rarely branched, binding hyphae of context 2-7 microns wide, colorless, thick-walled, nonseptate, with occasionally branching; hyphae of trama similar, (Gilbertson), spores 6-8 x 3-4 microns, cylindric to oblong elliptic, inamyloid, (Phillips), spores 7-8 x 3-3.5 microns, (Breitenbach)

7. Spore Print

   White (Buczacki).

Look-Alikes

1. Polyporus badius

   Is found on wood and has a bald stem, and the generative hyphae lack clamp connections, (Gilbertson). P. badius has similar colors but it has smaller pores (5-8 per mm), its fruits "on fallen branches and logs on the ground", and the stem is typically bald, (Ginns).

2. Polyporus varius

   Is found on wood, has a streaked cap, and has a bald stem, (Gilbertson).

3. Cerioporus leptocephalus

   Is usually much smaller and becomes whitish when old, besides being black only in the lower part of the stem.

Photo sources:

Photo 1 - Author: Friends of Aldinga Scrub (Attribution-NonCommercial 2.0 Generic)

Photo 2 - Author: Urmas Ojango (Attribution-NonCommercial 2.0 Generic)