Piptoporus betulinus

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by Michael Kuo

Anyone who has spent time in birch woods has seen Piptoporus betulinus on dead birch trees and logs, or occasionally on living trees. The species is an attractive polypore, easily recognized by its habitat on birch wood and the fact that the cap folds over to make a distinctive, smooth rim around the pore surface. The caps are whitish to brownish, and the pore surface is whitish or grayish brown. Although Piptoporus betulinus is annual and does not actually live for more than one season, its fruiting bodies are somewhat tough and are sometimes found in the next year (usually somewhat blackened).

Piptoporus betulinus is apparently edible when young (it was sampled, anyway, by Charles McIlvaine, who was to mushrooms the virtual opposite of what "Mikey" was to breakfast cereals, in that he would try eating just about anything that wasn't known to be poisonous), but it is quite a tough and corky mushroom, and I can't imagine the texture would make a pleasant eating experience. However, the fungus does have antibiotic and styptic properties--and the Tyrolean Ice Man was carrying it around for some reason (see right-hand column).

Description:

Ecology: Saprobic and possibly parasitic; growing alone or gregariously on dead birch trees, logs, and occasionally on living trees; found year-round; occurring wherever birch trees occur naturally. Piptoporus betulinus causes a yellowish to brown cubical rot, and is a powerful decomposer of dead wood. Whether or not it attacks living trees as a parasite is contended.

Cap: 5-25 cm; kidney-shaped in outline; broadly convex to more or less flat; growing shelf-like or hoof-like; dry; with a smooth or somewhat roughened "skin" that often peels away; whitish to pale brownish in age; the margin rolled over smoothly to form a rim around the pore surface.

Pore Surface: Whitish, aging grayish brown; 2-4 pores per mm; tubes to 1 cm long.

Stem: Absent or rudimentary and stubby.

Flesh: White; thick; corky.

Taste: Slightly bitter; odor strong and pleasant.

Spore Print: White.

Microscopic Features: Spores: 3-6 x 1.5-2 µ; smooth; cylindrical to long-elliptical. Cystidia absent.

REFERENCES: (Bulliard ex Fries) Karsten. (Overholts, 1953; Arora, 1986; Gilbertson & Ryvarden, 1987; Phillips, 1991/2005; Roody, 2003.) Herb. Kuo 09080102.

Further Online Information:

Piptoporus betulinus at Roger's Mushrooms
Piptoporus betulinus at Tree Diseases of BC
Piptoporus betulinus at Fungi of Poland

The Ice Man's Medicine

The Tyrolean Ice Man, who was frozen and mummified in the Copper Age, 5000 years ago, had among his possessions a curious pair of hide strips that held pieces of Piptoporus betulinus. Archaeologists speculate that the Ice Man used the birch polypore for medicinal purposes.

The South Tyrol Museum of Archaeology has kindly granted permission for use of the photo above. Visit the Museum's well designed and fascinating Web site to find out more about the Tyrolean Ice Man.

Photo copyright: Photo Archives of the South Tyrol Museum of Archaeology

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Cite this page as:

Kuo, M. (2004, January). Piptoporus betulinus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/piptoporus_betulinus.html