Hypsizygus tessellatus

[ Basidiomycetes > Agaricales > Tricholomataceae > Hypsizygus . . . ]

by Ron Meyers

The name Hypsizygus tessellatus (or "Hypsizygus tessulatus") has been applied to two different mushrooms, Hypsizygus ulmarius and Hypsizygus tessellatus, to the extent that it is often difficult to know which mushroom is being described in field guides or Web sites. However, research by Redhead (1986) clearly distinguishes the two mushrooms, which actually bear very little resemblance to each other. According to Redhead, Hypsizygus tessellatus has a small cap with crowded, round spots, and usually grows in clusters.

Part of the difficulty in finding good descriptions or photos probably derives from the fact that Hypsizygus tessellatus is not a common mushroom, and not widespread in North America. The best descriptions originate from the Pacific Northwest, leading to the conclusion that it is more prevalent there.

I have never seen this mushroom grow, but I have eaten it. In 1999, I posted a photo of Hypsizygus ulmarius on my Web site and mislabeled it "Hypsizygus tessulatus." Mushroomers from Washington informed me of my error and sent me a can of “Summer Mushroom,” grown in Taiwan. It was Hypsizygus tessellatus, and the photo on the can was one of the better representations I had seen, although the mushrooms had fairly dark caps on a white stem.

Hypsizygus tessellatus is a widely cultivated edible in Asia, particularly Japan, where it is known as hon-shimeji. It is available commercially as the "Beech Mushroom" in white or brown varieties on several Web sites in the United States, either in kits for cultivation or mature specimens for cooking. The mushroom described below is a light colored variation occurring in the Pacific Northwest; the photo represents darker, cultivated mushrooms from the United Kingdom.

Description:

Ecology: Saprobic; sometimes alone, but usually in dense clusters of seven or more individuals; often on poplars or maple, but occasionally found on beech, birch, elm or fir; sometimes in large groups high in the crotch of a dead tree, or in smaller groups on dead stumps or logs; apparently common in Pacific Northwest.

Cap: 2-4 cm; convex, becoming nearly flat at maturity; moist; smooth; buff or pinkish cream, with water droplets on the top that form a marbling pattern.

Gills: Attached to the stem or running down it; nearly distant; cross-veined; buff to pinkish buff.

Stem: 4-22 cm long; smooth except for white hairs at the base; white; with a soft center; usually central; equal or tapering at base; often curved or bent; without a partial veil.

Flesh: Firm but not tough; soft and cottony at the stem center; white to pinkish buff.

Taste: Not distinctive. Odor mild, faintly of anise or apricot.

Spore Print: Buff.

Microscopic Features: Spores 4-5 µ; smooth; round or nearly so.

REFERENCES: (Bulliard, Fries) Singer, 1947 (Brown, 1981; Redhead, 1986*; Schalkwijk-Barendsen, 1991.)

* Redhead, S. A. (1986). Mycological observations 15-16: on Omphalia and Pleurotus. Mycologia 78: 522-528.

Hypsizygus marmoreus, Hypsizygus elongatipes, and Pleurotus elongatipes are former names.

Hypsizygus tessulatus is sometimes mistaken for Lyophyllum decastes. They are similar in appearance, but the latter does not grow on wood.

© MushroomExpert.Com

Cite this page as:

Meyers, R. (2004, September). Hypsizygus tessellatus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/hypsizygus_tessellatus.html