Hebeloma Crustuliniforme: The Ultimate Mushroom Guide

About The Hebeloma Crustuliniforme Mushroom

Hebeloma Crustuliniforme is a gilled mushroom of the genus Hebeloma found in Europe and North America and has been introduced into Australia. Its specific name derives from the Latin crustulum or little biscuit. It is moderately poisonous.

This fungus can be mycorrhizal on both hardwoods and conifers. The mushroom can fruit in late summer or fall. Whitish or pale tan often with darker coloring in the center, and an inrolled margin when young.

This specimen when collected was white, but gills turned golden brown after drying.

Other names: Poison Pie, Fairy Cakes.

Hebeloma Crustuliniforme Identification

1. Ecology

   Mycorrhizal with hardwoods or conifers; growing gregariously or in loose clusters, sometimes in arcs or fairy rings, in grassy areas at woods' edges or in woods; late summer and fall (winter and spring in California); widely distributed in North America.

2. Cap

   3-11 cm; convex, becoming broadly convex, broadly bell-shaped, or flat; slimy when fresh; smooth; whitish, dirty buff, or pale tan - often with a somewhat darker central area; the margin inrolled when young.

3. Gills

   Attached to the stem, often by a notch; crowded; pale when young, becoming brownish; sometimes with beads of liquid when young and fresh--and, later, with brownish spots where the beads occurred; with whitish edges.

4. Stem

   4-13 cm long; 0.5-1.5 cm thick; more or less equal above a slightly swollen base; finely hairy or smooth; with little flakes of tissue near the apex; without a cortina or ring zone; the base sometimes with white rhizomorphs.

5. Flesh

   Whitish; thick.

6. Odor and Taste

   Odor radishlike; taste radishlike or bitter.

7. Spore Print

   Brown.

8. Microscopic Features

   Spores 9-13 x 5-7.5 µ; amygdaliform to limoniform; finely verrucose; not dextrinoid. Cheilocystidia abundant; apices subclavate to clavate; rarely basally inflated; 50-95 x 7-9 µ. Pileipellis an ixocutis.

9. Similar Species

   Hebeloma sinapizans is typically rather larger with a more bulbous stem base; it favors alkaline soil, has a persistent incurved cap margin until almost fully expanded, and has gills that do not release watery droplets that leave dark brown spots on the gills. It is, despite all the above, very difficult to separate these two species in the field from macroscopic characters alone.

Hebeloma Crustuliniforme Taxonomy & Etymology

This mushroom was described in 1787 by French mycologist Jean Baptiste Francois Pierre Bulliard, who gave it the name Agaricus crustuliniformis.

It was another Frenchman, Lucien Quélet, who in 1872 transferred this species to its current genus, whereupon its scientific name became Hebeloma crustuliniforme.

Synonyms of Hebeloma crustuliniforme include Agaricus crustuliniformis Bull., Agaricus crustuliniformis var. minor Cooke, and Hebeloma crustuliniforme var. minor (Cooke) Massee.

Watery droplets released from the gills of Hebeloma crustuliniforme, Poisonpie, Cambridgeshire, England

The generic name Hebeloma comes from two Ancient Greek words: hebe- means youth, and the suffix -loma means a veil. Thus mushrooms of this genus have a veil (the partial veil that covers the gills) only in the early stages of fruitbody development - when they are youthful. We come across that suffix -loma in several other fungi genera including Entoloma, and Tricholoma.

The specific epithet crustuliniforme means in the form of a thin crust of bread. Well, a nice crusty pastry topping does not make a poison pie palatable.