Panus rudis Fr.

Phylum: Basidiomycota - Class: Agaricomycetes - Order: Polyporales - Family: Polyporaceae

Panus rudis, Europe

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.

Distribution

Panus rudis occurs on dead deciduous hardwood in southern Europe. The few records from Britain might be due to confusion with Panus conchatus.

Panus rudis, USA

The picture immediately above shows a rosette of Panus rudis fruitbodies on a dead tree stump in Lacrosse, WI, USA and was kindly contributed by Andrea Aspenson.

Taxonomic 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. (Oyster mushrooms of the Pleurotus genus are, in contrast, classified in the order Agaricales.)

Etymology

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.

Just as it sounds, 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.

anus rudis, western Algarve, Portugal

Identification guide

Cap of Panus rudis

Cap

Usually semi-circular or oyster-shaped when growing on standing wood, but as shown in the picture above rosette forms sometimes occur when fruiting on dead wood lying on the ground. Caps are up to 10cm across, developing wavy margins; tough; densely fuzzy; reddish to purplish-brown when young, fading to tan with age.

Stem

Nearly always eccentrically attached; very stubby and often invisble because it is embedded within the substrate; paler than the cap; usually fuzzily textured.

Gills of Panus rudis

Gills

Pale mauve or pale purple when young and fresh, turning paler and later browning with age; decurrent to the stem.

 

Spores

Ellipsoidal, smooth, 4.5-6.5 x 2.5-4µm; inamyloid.

Spore print

White or very pale yellow.

Odour/taste

Not distinctive.

Habitat & Ecological role

Restricted to dead hardwood - usually on fallen trunks and branches, particularly oaks.

Season

Summer through to winter and often into spring in mild parts of southern Europe.

Similar species

Panrus conchatus is similar but scaly rather than fuzzy, and its spores are slightly longer and narrower (a higher Q value); it is occasionally found in Britain and other northern European countries.

Panus rudis, Portugal

Culinary Notes

This species is not generally considered edible, and we have no information about whether it contains toxins; however, Panus rudis as found in North America is stated by Clyde Martin Christensen (see Reference Sources, below) to be edible but tough.

Reference Sources

Fascinated by Fungi, Pat O'Reilly 2016.

Clyde Martin Christensen (1981), Edible Mushrooms; ISBN: 0-8166-1049-5; University of Minnesota Press.

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.

Other web pages about this species

Michael Kuo (USA)

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