Tricholoma inamoenum

What You Should Know

Tricholoma inamoenum is a poisonous mushroom of the agaric genus Tricholoma. It can be recognized by its small, cream to pale tan fruit bodies with a strong, coal-tar odor and very large spores. Habitat solitary to gregarious in duff under conifers (especially Sitka spruce); uncommon, fruiting from fall to midwinter in coastal forests from Mendocino County northward.

Other names: Irksome Cavalier, Ill-scented Tricholoma.

Tricholoma inamoenum Mushroom Identification

1. Cap

   The cap is 15 - 60 (80) mm, at first hemispherical or broadly conical, with a tucked inward edge; when ripe, it opens to flat-convex or prostrate with a tubercle in the center, less often concave. The surface is smooth, dull, whitish, or pale yellow, darker with age and closer to the center, with an ocher or coral tint.

   The plates are adherent with a tooth, white or slightly yellowish, rather sparse and wide.

2. Stem

   The stem is usually rather thin and slender, 50–120 mm long, 3–13 (18) mm in diameter, cylindrical or slightly widening towards the base, smooth, fibrous, with a white felt coating at the base; the same shades as the hat, usually brighter and darker downward.

3. Flesh

   The flesh is white or with the same shade as the color of the cap. The smell is very characteristic: strong, unpleasant, "chemical"; coke oven gas smells the same; powdery notes appear on the break in the smell.

4. Microscopy

   Spores 8.1 - 13.0 × 5.5 - 8.2 µm, Q = 1.2 - 1.9, ellipsoidal. Basidia 40 - 55 × 9 - 12 µm, mostly 4-spore, sometimes with a buckle at the base. Cheilocystids are absent. Pileipellis is a thin cutis, hyphae consist of elements 12 - 60 × 2 - 7 µm.

5. Ecology and Distribution

   Grows singly or in small groups on slightly acidic and calcareous soils, usually deep in moss. Forms mycorrhiza with fir (Abies) and spruce (Picea). The species is common in the taiga zone of Western Siberia.

6. Fruiting

   End of July - October.

7. Similar Species

   Tricholoma sulphureum shares this repugnant odor but is yellow overall, and the cap surface becomes violet in KOH.

Sources:

Photo 1 - Author: Gerhard Koller (Gerhard) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 2 - Author: Jacob Kalichman (Pulk) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 3 - Author: walt sturgeon (Mycowalt) (Creative Commons Attribution-Share Alike 3.0 Unported)