Tricholoma magnivelare

Description

Tricholoma magnivelare is a gilled mushroom found East of the Rocky Mountains in North America growing in coniferous woodland. These ectomycorrhizal fungi are typically edible species that exist in a symbiotic relationship with various species of pine, commonly jack pine. It is recognized by the stocky stature, overall white color, often with brown fibrils or scales on cap and lower stipe, thick stipe that usually tapers to a pointed base and bears a large cottony ring, and firm flesh with a characteristic spicy odor.

While tough, the mushroom can be eaten both raw and cooked and is considered a choice.

The name "Tricholoma magnivelare" has long been used for the western North American matsutake, but recent research (Trudell et al. 2017) indicates that Tricholoma magnivelare is only found in eastern North America, while the range of Tricholoma murrillianum extends from the Rocky Mountains to the West Coast.

Common names: American Matsutake, White Matsutake, Pine Mushroom.

Mushroom Identification

1. Ecology

   Mycorrhizal, primarily with conifers (including lodgepole pine and other true pines, Douglas-fir, hemlock, and fir), but also found in association with tanoak and madrone on the West Coast; growing alone, scattered, or gregariously; western North America from the Rocky Mountains westward; fall, and (in warmer climates) winter.

2. Cap

   5–10 cm; convex becoming broadly convex or nearly flat; dry or a little sticky; white at first, but often developing brownish to brown appressed fibrils and small scales; the margin inrolled when young.

3. Gills

   Narrowly attached to the stem, sometimes through a notch; close; short-gills frequent; white to ivory; sometimes developing brown or reddish-brown stains and spots with age; at first covered by a white partial veil.

4. Stem

   4–10 cm long; 1–2.5 cm thick; more or less equal, or with a slightly tapered base; white above the ring, but developing brown colors, like the cap, below; partial veil white and thick, collapsing to form a sheath around the lower stem and a prominent flaring ring at the top edge of the sheath.

5. Flesh

   White; firm; not changing on exposure.

6. Odor and Taste

   Odor is strong, fragrant, and distinctive; tastes spicy.

7. Chemical Reactions

   KOH negative on cap surface.

8. Spore Print

   White.

9. Microscopic Features

   Spores 5–8 x 4–6 µm; ellipsoid to nearly subglobose, with a small apiculus; smooth; hyaline in KOH, often with one large oil droplet; inamyloid. Cystidia not found. Pileipellis a cutis; elements 5–7.5 µm wide, smooth, hyaline to yellowish in KOH. Clamp connections not found.

Synonyms

1. Agaricus ponderosus Peck (1873)

2. Agaricus magnivelaris Peck (1878)

3. Armillaria ponderosa Sacc. (1887)

4. Armillaria arenicola Murrill (1912)

5. Armillaria magnivelaris (Peck) Murrill (1914)

6. Tricholoma ponderosum (Sacc.) Singer (1951)

7. Tricholoma murrillianum

Photo sources:

Photo 1 - Author: Ron Pastorino (Ronpast) (CC BY-SA 3.0)

Photo 2 - Author: Ron Lawrence (Rondango) (CC BY-SA 3.0)

Photo 3 - Author: Bill (boletebill) (CC BY-SA 3.0)

Photo 4 - Author: Ryane Snow (snowman) (CC BY-SA 3.0)