What You Should Know
Tricholoma vaccinum is a fungus of the agaric genus Tricholoma. It produces medium-sized fruit bodies (mushrooms) that have a distinctive hairy reddish-brown cap with a shaggy margin when young. The cap, which can reach a diameter of up to 6.5 cm (2.6 in) wide, breaks up into flattened scales in maturity. It has cream-buff to pinkish gills with brown spots. Its fibrous, hollow stipe is white above and reddish-brown below, and measures 4 to 7.5 cm (1.6 to 3.0 in) long.
The young fruit bodies have a partial veil, it does not leave a ring on the stipe. Widely distributed.
Tricholoma vaccinum grows in a mycorrhizal association with spruce or pine trees, and its mushrooms are found on the ground growing in groups or clusters in late summer and autumn. Although some consider the mushroom edible, it is of poor quality and not recommended for consumption.
Other names: Russet Scaly Tricholoma, Scaly Knight, Fuzztop.
Tricholoma vaccinum Mushroom Identification
Mycorrhizal, primarily with spruces but occasionally with other conifers; growing alone, scattered, or gregariously; late summer and fall (also overwinter in warm climates); widely distributed in northern and montane North America.
3–10 cm; convex, becoming broadly convex or broadly bell-shaped, and eventually nearly flat; dry; covered with radial fibrils that become separated and aggregated into scales with maturity; orangish brown to reddish-brown, often with a darker center; fading to orangish tan with age; the margin at first inrolled and fuzzy (appearing like a cortina when appressed to the stem), later becoming lacerated and hairy.
Broadly attached to the stem or attached by a notch; close; short-gills frequent; whitish to very pale yellowish; often discoloring and spotting brownish to orangish brown.
4–10 cm long; 1–2 cm thick; often tapered to the base; whitish or pale orangish and fairly smooth at the top, but fibrillose to scaly below; usually becoming hollow; basal mycelium white.
Whitish to pale pinkish; not changing on exposure.
Odor and Taste
The odor usually mealy but sometimes fruity and sweet, or not distinctive; taste mealy, bitter, or not distinctive.
KOH negative, gray, purplish, or reddish to brown on cap surface.
Spores 5–8 x 4–5.5 µm; broadly ellipsoid; smooth; hyaline in KOH; inamyloid. Basidia 4-sterigmate. Pleurocystidia and cheilocystidia not found. Lamellar trama parallel. Pileipellis a cutis of cylindric elements 5–10 µm wide; hyaline to orangish brown in KOH.
Tricholoma vaccinum Look-Alikes
Somewhat resembles T. vaccinum, but has duller brown colors, is less robust in stature, and has a solid (not hollow) stalk.
Has a less woolly cap texture and flesh that turns bright pinkish-red when injured. It associates solely with pine species and prefers calcareous soil.
Tricholoma vaccinum Taxonomy and Etymology
The species was first described in 1774 by German mycologist Jacob Christian Schäffer as Agaricus vaccinus. According to MycoBank, synonyms include August Batsch's 1783 Agaricus rufolivescens, Jean-Baptiste Lamarck's 1783 Amanita punctata var. punctata, and Lucien Quélet's 1886 Gyrophila vaccina. Marcel Bon described the variety T. vaccinum var. fulvosquamosum in 1970, which has squamules (minute scales) arranged concentrically on the cap; Manfred Enderle published this taxon as a form in 2004.
According to the infrageneric classification of Tricholoma proposed by Rolf Singer in 1986, Tricholoma vaccinum is placed in the section Imbricata, subgenus Tricholoma in the genus Tricholoma. Imbricata includes species with a dry cap cuticle, with a texture that ranges from roughened or squamulose (resembling suede) to almost smooth. The specific epithet derives from the Latin word vaccinus and means "cow-colored".
Photo 1 - Author: Ron Pastorino (Ronpast) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 2 - Author: Holger Krisp (Creative Commons Attribution 3.0 Unported)
Photo 3 - Author: Sava Krstic (sava) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 4 - Author: Irene Andersson (irenea) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 5 - Author: Holger Krisp (Creative Commons Attribution 3.0 Unported)