Hebeloma sinapizans
Description
Hebeloma sinapizans is a species of mushroom in the family Hymenogastraceae. It has a strong radish-like smell, and a prominent bulbous stem base. It is larger than the similar and more common H. crustuliniforme, a relative that is also poisonous. H. sinapizans is found in Europe and North America.
Also, Hebeloma sinapizans has a more swollen stem base and is found in chalk or limestone areas where the soil is alkaline. In Britain and Ireland, beechwoods are the most common habitat for this mycorrhizal fungus.
Common names: Rough-Stalked Hebeloma, The Bitter Poisonpie.
Mushroom Identification
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 woods; late summer and fall (winter and spring in California); widely distributed in North America.
Cap
4-15 cm; convex or broadly convex, becoming flat; sticky when fresh; bald; with a soft, cottony margin when young; sometimes with a whitish sheen when young; cinnamon tan to darker reddish-brown.
Gills
Attached to the stem, often by a notch; close; pale clay color when young, becoming cinnamon brown to brown; sometimes with beads of liquid when young and fresh; the edges often becoming ragged as the mushroom matures.
Stem
4-12 cm long; 1-3 cm thick; more or less equal above a fairly abrupt, swollen base; finely mealy or dusty near the apex; developing scales below, often in more or less concentric bands; whitish, but the scales often capturing spores as the mushroom matures and thus becoming brownish; without a cortina or a ring zone.
Flesh
Whitish; thick.
Odor and Taste
Radishlike.
Chemical Reactions
KOH gray on cap surface.
Spore Print
Brown to pinkish brown.
Microscopic Feature
Spores 11-15 x 6.5-8 µ; sublimoniform, with a snout-like end; finely verrucose; rarely with a loosening perispore; moderately dextrinoid. Cheilocystidia 33-80 x 6-10 µ; abundant; clavate, subcapitate, or sometimes merely cylindric - but rarely ventricose. Pileipellis an ixotrichoderm in young specimens; later an ixocutis.
Similar Species
Hebeloma crustuliniforme is typically rather smaller with a less bulbous stem base; it often occurs on acidic soil, does not have a persistent incurved cap margin, and has gills that in wet weather release watery droplets that dry as dark spots on the gills. It is, despite all the above, very difficult to separate these two species in the field from macroscopic characters alone.
History
This mushroom was described in 1793 by French mycologist Jean-Jacques Paulet (1740 - 1826) who gave it the binomial scientific name Hypophyllum sinapizans. It was another Frenchman, Claude-Casimir Gillet (1806 - 1896), who in 1874 transferred this species to the genus Hebeloma, whereupon its currently-accepted scientific name Hebeloma sinapizans was established.
Synonyms of Hebeloma sinapizans include Hypophyllum sinapizans Paulet, and Agaricus sinapizans (Paulet) Fr.
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 sinapizans comes from Latin sinapis which means mustard; it is a reference to the typical yellowish-ochre color of caps of the Bitter Poisonpie.
Photo sources:
Photo 1 - Author: Agnes Monkelbaan (CC BY-SA 4.0)
Photo 2 - Author: Jerzy Opioła (CC BY-SA 3.0)
Photo 3 - Author: Jerzy Opioła (CC BY-SA 3.0)
Photo 4 - Author: bogsuckers (CC BY-SA 4.0)
