Panus neostrigosus

Description

Panus is a small genus of tough wood-rotting fungi whose fruitbodies are usually purple-tinged when young and fresh; they grow rather like oyster mushrooms or Split Gill fungi, with a very short eccentric stem, wavy margins, and shallowish gills that fork.

Panus neostrigosus is an inedible but not toxic mushroom.

The degree of color change is remarkable and can occur in a single day. DNA information places this gilled mushroom among the polypores, indicating the independent evolution of gills.

Common names: Hairy Oyster Mushroom.

Mushroom Identification

1. Ecology

   Saprobic on the wood of recently dead hardwoods; growing alone, gregariously, or in clusters; spring through fall (also overwinter in warm climates); widely distributed in North America.

2. Cap

   2–6 cm wide; convex with a tightly inrolled margin at first, becoming depressed or vase-shaped with an even margin; round in outline or tongue-shaped to irregular; densely hairy with hairs 1–2 mm long; dry; often purple at first, but soon fading to reddish-brown, pinkish brown, orangish brown, or tan.

3. Gills

   Running down the stem; close or crowded; short-gills frequent; sometimes purplish when fresh and young, but soon white; eventually pale brownish.

4. Stem

   1–2 cm long; up to 1 cm wide; often off-center or lateral; equal above a slightly swollen base; tough; dry; densely hairy; colored like the cap or paler.

5. Flesh

   Whitish; unchanging when sliced; rather tough and stringy.

6. Odor and Taste

   Odor not distinctive; taste not distinctive, or sometimes bitter.

7. Spore Print

   White.

8. Microscopic Features

   Spores 4–5.5 x 1.5–2 µm; cylindric to long-ellipsoid; smooth; hyaline in KOH; inamyloid. Cheilo- and pleurocystidia 25–65 x 5–15 µm; cylindric, subclavate, or subutriform; smooth; developing very thick walls; hyaline in KOH. Basidia 20–25 x 3–4 µm; subclavate; 4-sterigmate. Pileipellis brown to golden brown in KOH; a poorly defined, partially gelatinized layer from which arise aggregations of erect elements 2.5–5 µm wide, clamped at septa, golden-walled and smooth; terminal cells cylindric with rounded, subacute, or subcapitate apices.

9. Similar Species

   Lentinus strigosus occurs on dead deciduous hardwood in southern Europe.

History

Despite having gills, fungi in the genus Panus are now thought to be much more closely related to the Polypores than to the Agaricales - another example of parallel evolution.

Panus, the genus name, probably comes from Greek and means a swelling or tumour (a growth, therefore). Swedish mycologist Elias Magnus Fries described and named this species in 1838.

The specific epithet rudis comes from the same stem as 'rudimentary' and means basic, rough or raw (in the sense of uncultivated); this suggests a mushroom of lower esteem than other (oyster-like) species of similar appearance.

Synonyms for this mushroom are many. It has been known as Lentinus rudis—but Pegler (1983) synonymized these names with Panus/Lentinus strigosus. The species epithet strigosus, originally used by Fries (1825) has been problematic because of competition from an entirely different "Panus strigosus," named by Berkeley & Curtis (1859), now generally known as Pleurotus levis. To clear up the confusion Drechsler-Santos and collaborators (2012) provided a new species name: neostrigosus.

Photo sources:

Photo 1 - Author: Judi T. (AvidAmateur) (CC BY-SA 3.0)

Photo 2 - Author: Katja Schulz from Washington, D. C., USA (CC BY-SA 2.0)

Photo 3 - Author: Rich Hoyer (Rich Hoyer) (CC BY-SA 3.0)