Hebeloma sinapizans, commonly known as the scaly-stalked heboloma,[1] rough-stalked hebeloma or the bitter poisonpie, is a species of mushroom in the family Hymenogastraceae. It has a strong radish-like smell and a prominent bulbous stem base. H. sinapizans is found in Europe and North America and is poisonous.
First described as Hypophyllum sinapizans by Jean-Jacques Paulet in 1793, it was transferred to the genus Hebeloma by Claude Casimir Gillet in 1878. It is commonly known as the "rough-stalked Hebeloma".
The fruit body has a cap that is initially convex before flattening out in age, reaching a diameter of 4–. The cap may have a shallow umbo. The cap surface ranges from moist to sticky, and it is smooth with a margin that is first curled inward and expanding to become curled upward in maturity; the cap color is whitish-tan to cinnamon-tan, sometimes with pinkish- or reddish-brown tints. The flesh is whitish, thick, and has a radish-like odor and taste. Gills have an adnate attachment to the stipe, and they have a notch just before the point of attachment; the gill edges have tiny fringes or serrations. They are first whitish before turning to yellowish-brown to pale brown after the spores mature.
The stipe measures 2– long by 1.3– thick, and is roughly equal in width throughout its length.
Fruit bodies produce a pale brown spore print. Spores are elliptical with a rough surface texture, and measure 10–14 by 6–8 μm.
It is similar to the more common H. crustuliniforme, a smaller relative that is also poisonous.
As of December 2022, the species has been found in 20 countries across Europe as well as in Asiatic Turkey and Lebanon.[2]
The fungus fruits on the ground in groups or fairy rings in deciduous and coniferous forests.
H. sinapizans mushrooms are poisonous.