Polyporus brumalis (Pers.) Fr. - Winter Polypore

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

Polyporus brumalis - Winter Polypore

Polyporus brumalis is a winter polypore that grows on fallen branches of deciduous trees. The pores of these thin-capped polypores cannot be detached from the upper layer of the cap. Tough and inedible, these are not fungi to gather as food; however, the dried caps are sometimes used as table decorations or as inert contributors to pot pouri.

Because it is such a late species, this fascinating fungus is commonly called the Winter Polypore.

Polyporus brumalis - Winter Polypore, Slovenia

Distribution

Polyporus brumalis is fairly common and widespread across most of Britain and Ireland. It occurs also throughout mainland Europe and in many parts of Asia and North America.

Well camouflaged among the fallen leaves, these brown funnel-shaped caps can be difficult to spot, but when you do come across one there is often a small group on the same fallen log.

Taxonomic history

The Winter Polypore was described scientifically in 1794 by Christiaan Hendrik Persoon, who created its basionym when he gave it the scientific binomial name Boletus brumalis. in 1821 the Swedish mycologist Elias Magnus Fries transferred this species to its current genus, at which point its currently-accepted scientific name Polyporus brumalis was established.

Polyporus brumalis - Winter Polypore, Wales

Synonyms of Polyporus brumalis include Boletus fuscidulus Schrad., Boletus brumalis Pers., and Polyporus fuscidulus Schrad.) Fr.

Etymology

The generic name Polyporus means 'having many pores', and fungi in this genus do indeed have tubes terminating in pores (usually very small and a lot of them) rather than gills or any other kind of hymenial surface.

The specific epithet brumalis means 'of winter' and is another reference to the emergence of this species mainly in the cooler months of the year.

The fruitbodies of this tough little polypore are very slow to rot (and bugs must find many other fungi much easier to chew!). As a result you can expect to find Winter Polypores all through summer, albeit with darkened pore surfaces (see left) and no longer producing spores.

Identification guide

Cap of Polyporus brumalis

Cap

The upper surface of the cap of this occasional polypore is smooth and usually grey-brown but very variable in colour and often zonate. As they age, the fruitbodies become much darker.

2 to 8cm in diameter and with cap flesh 1 to 5mm thick, the fruiting bodies usually have inrolled and often somewhat wavy margins. The flesh is white and leathery, becoming very hard in dry weather.

Underside (pores) of Polyporus brumalis

Tubes and pores

Beneath the cap, the white tubes are packed together at a density of 2-3 per mm; they are between 0.1 and 0.4mm deep and terminate in whitish pores that turn buff as they age.

 

Spores

Cylindrical or sausage-shaped, smooth, 4-7 x 2-2.5µm; inamyloid.

Spore print

White.

Odour/taste

Odour faintly mushroomy; taste not distinctive.

Habitat & Ecological role

Saprobic, restricted to dead hardwood - usually fallen branches and particularly Beech.

Season

Late autumn through to the end of spring.

Similar species

Polyporus ciliatus is very similar but has much smaller, more densely packed pores.

Culinary Notes

This polypore fungus is too tough and insubstantial to be of any culinary interest.

Reference Sources

Mattheck, C., and Weber, K. (2003). Manual of Wood Decays in Trees. Arboricultural Association

Pat O'Reilly (2016). Fascinated by Fungi, First Nature Publishing

BMS List of English Names for Fungi

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

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

Roger Phillips (UK)

Michael Kuo (USA)

Marek Snowarski (Poland)

Top of page...


Fascinated by Fungi, 2nd edn, hardback

If you have found this information helpful, we are sure you would also find our book Fascinated by Fungi by Pat O'Reilly very useful. Author-signed hardback copies at a special discount price are available here...

Other nature books from First Nature...