Cystoderma carcharias

Description

Cystoderma carcharias is a species of agaric in the fungal family Agaricaceae. It is widespread and collected in coniferous forests and grasslands in Asia, Europe, North America, and the subantarctic islands. In the field, fruit bodies are characterized by a pink cap up to 6 cm (2.4 in) broad, a well-developed ring on the stem, and an unpleasant odor.

Cystoderma carcharias accumulates cadmium in its fruiting bodies. In polluted areas, cadmium concentrations may even exceed 600 mg/kg in dry mass. Furthermore, C. carcharias contains numerous organoarsenic compounds.

Common names: Pearly Powdercap.

Mushroom Identification

1. Cap

   The cap 1.5-4.0 cm broad, convex, expanding to plano-convex, sometimes with a low umbo; margin at first slightly inrolled and fused to a sheathing stipe, then decurved, occasionally appendiculate, finally nearly plane; surface covered with superficial granules or small erect scales, most of which weather away in age leaving only a scattering of powdery granules; color: rusty-brown to yellow-brown; flesh thin except at the disc, colored like the cap; odor and taste mild.

2. Gills

   The gills adnexed, close, narrow, white, cream to pale yellowish.

3. Stipe

   Stipe 2-6 cm long, 3-7 mm thick, more or less equal, solid to stuffed; the apex smooth to appressed fibrillose, cream to pale yellow; below the ring, a sheathing, granulose, rusty-brown to ochraceous-brown veil, at maturity forming a persistent, membranous, median to superior, flaring ring, pallid on the upper surface, the lower surface like the cap and lower stipe.

4. Spores

   Spores 4-5.5 x 3-4 µm, broadly elliptical, smooth, amyloid; spore print white.

5. Habitat

   Solitary, scattered, or in small clusters on moss, rotten logs, and needle duff in conifer woods; fruiting after the fall rains.

6. Similar Species

   Cystoderma amianthinum, is similarly colored and ornamented but lacks a well-developed veil and persistent ring.

History

The species was first described scientifically by Christian Hendrik Persoon, who named it Agaricus carcharias in 1794. Swiss mycologist Victor Fayod assigned it its current name in 1889. The specific epithet carcharias is probably derived from the Greek καρχαρός (karcharos) which means sharp, pointed, or jagged. καρχαρίας (karcharias) is translated as a shark.

Photo sources:

Photo 1 - Author: Andreas Kunze (CC BY-SA 3.0)

Photo 2 - Author: Jerzy Opioła (CC BY-SA 4.0)

Photo 3 - Author: Jerzy Opioła (CC BY-SA 4.0)

Photo 4 - Author: Jerzy Opioła (CC BY-SA 3.0)

Photo 5 - Author: Andreas Kunze (CC BY-SA 3.0)