Beech mushroom

What it is

The beech mushroom is a gilled fungus that grows in clusters on hardwood, often high on the trunk, and is frequently found on beech trees, which gives it its common name. Its Japanese commercial names are buna-shimeji, the brown beech or brown clamshell mushroom, and bunapi-shimeji, the white beech or white clamshell mushroom. The white form is a UV-induced mutant of the brown wild type, according to the Wikipedia article.

The scientific name is unsettled. The article treats Hypsizygus tessulatus as the accepted name, with H. marmoreus, H. elongatipes and Pleurotus elongatipes as synonyms, and notes that some DNA barcoding work treats all members of the genus as one species. The catalogue record uses Hypsizygus marmoreus and H. tessulatus as search names. The trade often spells the epithet tessellatus.

Where it grows and how it is produced

In the wild it is saprotrophic, growing singly or in scattered groups on hardwood. The Wikipedia article lists it as native to East Asia, with the note that this needs a citation, and says it is common in northern North America. Cultivated beech mushrooms are grown in temperate parts of Europe, North America and Australia, and sold fresh in supermarkets.

The article gives no cultivation history or dates. It records only that the bunapi strain was registered by Hokto Corporation, without a year. The sources used here therefore do not say when the mushroom entered cultivation or how it was first grown.

How it is cooked

The beech mushroom is tough and somewhat bitter when raw, so it should be cooked. Cooking removes the bitterness and leaves a firm, slightly crunchy texture and a nutty flavour. It is used in stir-fries, soups, stews, sauces, nabe hotpots and takikomi gohan. It can be sauteed whole, or slow-roasted with a little butter or oil.

The clusters are usually separated into small pieces before cooking. Because the caps stay firm, the mushroom holds its shape in long simmering, which is why it suits nabe.

Limits of the sources

The sources reviewed here give no yields, no substrate recipes, no shelf life and no storage method. This page gives none. The wild range is a lead, not a measured distribution, and the point about the East Asian native range is marked by the source as needing a citation.