Royoporus badius

What You Should Know

Royoporus badius or Picipes Badius is a species of fungus in the family Polyporaceae. It causes a white rot of hardwoods and conifers. The species is found in temperate areas of Asia, Australia, Europe, and North America. It has a dark brown or reddish-brown cap that reaches a diameter of 25 cm (9.8 in), and a stipe that is often completely black or brown at the top and black at the base.

The black-footed polypore gains its name from the black stipe supporting the fruiting body. Large specimens are unmistakable and easy to identify.

Other names: Black-Footed Polypore, Black-Leg.

Royoporus badius Mushroom Identification

1. Ecology

   Saprobic on the deadwood of hardwoods (also occasionally reported on the wood of conifers); usually appearing after the bark has begun to decay, or when it is entirely gone; causing a white rot; growing alone or gregariously; spring and fall - and over winter in warms spells or in warm climates; widely distributed in North America.

2. Cap

   4–20 cm; broadly convex to shallowly depressed; round, kidney-shaped, or lobed in outline; dry; bald; usually dark reddish-brown to dark brown, but paler towards the margin - but sometimes pale (nearly white) overall, with a reddish-brown center area; blackening slowly from the center outward with old age.

3. Pore Surface

   Running down the stem; white, becoming dingy whitish to brownish in age; not bruising where damaged; pores at first appearing "stuffed," later circular and very tiny (4–6 per mm; often invisible without a hand lens); tube layer 0.5–1 mm deep, not easily separable from the cap.

4. Stem

   Central or off-center to lateral; 1–4 cm long; 0.5–2 cm wide; equal, or tapered to base; dry; pale at the apex but dark brown to black and velvety elsewhere; tough.

5. Flesh

   White; unchanging when sliced; thin; very tough.

6. Spore Print

   White; often very difficult to obtain.

Royoporus badius Taxonomy

The species was first described in the scientific literature in 1801 by Christian Hendrik Persoon, who named it Boletus badius. American mycologist Lewis David de Schweinitz transferred the species to Polyporus in 1832, and it was known by this name until 1997, when De transferred the species into the genus Royoporus, which he had described the year before.

Polyporaceae species that are closely phylogenetically related to R. badius include P. dictyopus, P. melanopus, and P. tubaeformis, which have clamp connections on generative hyphae and a similar ecology. Zmitrovich & Kovalenko proposed the new genus Picipes for this fungus together with P. melanopus and P. tubaeformis and according to Species Fungorum Picipes badius is now the correct current name.

The specific epithet badius derives from the Latin root badi-, meaning "reddish-brown".

Sources:

Photo 1 - Author: Ron Pastorino (Ronpast) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 2 - Author: Holger Krisp (Creative Commons Attribution 3.0 Unported)

Photo 3 - Author: Σ64 (Creative Commons Attribution 3.0 Unported)

Photo 4 - Author: Dan Molter (Creative Commons Attribution-Share Alike 3.0 Unported)