Neofavolus alveolaris

What You Should Know

Neofavolus alveolaris is a species of polypore fungus in the family Polyporaceae. Found on sticks and decaying logs, its distinguishing features are its yellowish to the orange scaly cap, and the hexagonal or diamond-shaped pores. Become cream to white when dry. The pores on the cap underside are angular to hexagonal and relatively large (0.5–3 mm diameter). The fungus causes a white rot in hardwoods.

It is widely distributed in North America, Asia, Australia, and Europe.

There has always been confusion regarding the proper name for this mushroom; it has been placed in Polyporus and Favolus, among other genera. The most recent study (Sotome et al., 2013), however, erects the new genus Neofavolus for our little orange friend and its close relatives (all from Asia) based on molecular and morphological evidence.

Favolus alveolaris, Polyporus alveolaris, and Polyporus mori are synonyms.

Other names: Hexagonal-pored polypore.

Neofavolus alveolaris Mushroom Identification

1. Ecology

   Saprobic on recently-dead sticks and small logs (occasionally on living branches) of hardwoods, when the bark is still attached; causing a white rot; growing alone, scattered, or gregariously; typically first appearing in late spring, but frequently found in summer and fall; widely distributed and common east of the Rocky Mountains.

2. Fruiting Body

   2-7 cm across; fan-shaped, semicircular, or kidney-shaped; upper surface orange to orangish when fresh and young, fading with age to yellowish or nearly white, radially fibrillose to scaly (at least at first), dry, bald; typically featuring a short and stubby lateral stem, but occasionally with a centrally located and more substantial stem (in which case the cap is round, rather than kidney-shaped); pore surface descending the stem, whitish to pale orangish; pores to 1 mm wide and 2 mm long, diamond-shaped or "honeycombed," usually radially arranged; flesh to 2 mm thick, white, tough, unchanging when sliced.

3. Odor and Taste

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

4. Chemical Reactions

   KOH dull olive on fresh cap; negative on flesh.

5. Spore Print

   White.

6. Microscopic Features

   Spores 8-14 x 2.5-4 µ; subcylindric; smooth; hyaline in KOH. Basidia 4-spored. Pileipellis a cutis of somewhat agglutinated, hyaline to brownish, clamped elements 2-3 µ wide. Hyphal system dimitic.

Sources:

Photo 1 - Author: Alan Rockefeller (Creative Commons Attribution-Share Alike 4.0 International)

Photo 2 - Author: Shirley Zundell (Creative Commons Attribution 4.0 International)

Photo 3 - Author: Jason Hollinger (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 4 - Author: Andreas Kunze (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 5 - Author: Andreas Kunze (Creative Commons Attribution-Share Alike 3.0 Unported)