Hebeloma mesophaeum
Description
Hebeloma mesophaeum is a smallish agaric that has a greasy cap with a dark brown center and paler margin, clay gills, and pale stem with a ring. It grows solitary or in small groups on soil, mostly with conifers in late summer to autumn.
This mushroom occurs most often under pine trees in late summer and autumn, where it sometimes grows in very large groups. This infrequently encountered mycorrhizal species is very slimy and sticky in wet weather.
Common names: Veiled Poisonpie.
In Mexico, this species is eaten and widely marketed.
Mushroom Identification
Ecology
Mycorrhizal with various conifers, including pines, spruces, and firs; usually growing gregariously; fall, winter, and spring (also in summer at higher elevations); widely distributed in North America.
Cap
2-7 cm; convex, becoming broadly convex, broadly bell-shaped, or nearly flat; sticky when fresh; bald; brown to pinkish brown over the center; often paler toward the margin; the margin with or without veil remnants.
Gills
Attached to the stem, often by a notch; close or crowded; creamy or faintly pinkish when young, becoming brownish.
Stem
2-9 cm long; up to 1 cm thick; more or less equal; silky; whitish at first, discoloring brownish to brown, from the base up, with maturity; sometimes with a faint or more prominent ring zone.
Flesh
Whitish.
Odor and Taste
Odor radishlike, or not distinctive. Taste radishlike or bitter.
Chemical Reactions
KOH negative on cap surface.
Spore Print
Brown to pinkish brown.
Microscopic Features
Spores 8.5-11 x 5-7 µ; ellipsoid; very finely verrucose (nearly smooth); not dextrinoid. Cheilocystidia to about 70 x 7 µ; abundant; cylindric above a ventricose base. Pileipellis an ixocutis 50-200 µ thick.
History
This mushroom was described in 1828 by Christiaan Hendrik Persoon, who gave it the scientific binomial name Agaricus fastibilis var. mesophaeus and, ten years later, the name Agaricus mesophaeus.
It was French mycologist Lucien Quélet who, in 1872, transferred this species to the genus Hebeloma, whereupon the Veiled Poisonpie mushroom acquired its currently-accepted scientific name of Hebeloma mesophaeum.
Synonyms of Hebeloma mesophaeum include Agaricus fastibilis var. mesophaeus Pers., Agaricus mesophaeus (Pers.) Fr., Agaricus strophosus Fr., Hebeloma mesophaeum var. mesophaeum (Pers.) Quél., Agaricus mesophaeus var. minor Cooke, Hebeloma strophosum (Fr.) Sacc., Hebeloma mesophaeum var. minor (Cooke) Massee, Hebeloma flammuloides Romagn., and Hebeloma mesophaeum var. strophosum (Fr.) Quadr.
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 mesophaeum means with a dusky middle.
Photo sources:
Photo 1 - Author: Drew Parker (mycotrope) (CC BY-SA 3.0)
Photo 2 - Author: Ron Pastorino (Ronpast) (CC BY-SA 3.0)
Photo 3 - Author: Jerzy Opioła (CC BY-SA 4.0)