Tricholoma scalpturatum

Description

Tricholoma scalpturatum is a species of agaric fungus in the family Tricholomataceae. Found in Europe, it grows in a mycorrhizal association with deciduous trees including Quercus, Fagus, Tilia, and Populus, and occasionally with Pinus.

The cap is conical initially, flattening to a convex shape. Measuring 4 to 8 cm in diameter, it is covered with scales, it is paler than many other tricholomas, and has crowded white or pale grey gills which often slowly stain lemon yellow when bruised.

Common names: Yellowing Knight.

Mushroom Identification

1. Cap

   4 to 8 cm in diameter when fully mature, the caps are usually grey, darker in the center and with paler margins that tend to become yellowish with age. The gray-brown fibrous surface scales are progressively denser and darker (sometimes almost black) towards the center of the cap. Caps are broadly convex, generally retaining a downturned margin and a very shallow umbo.

2. Gills

   Moderately well spaced apart, the gills are adnate to emarginate, broad, white at first, yellowing with age.

3. Stem

   Typically 10 to 20mm in diameter and 4 to 8cm long, more or less cylindrical, the stem is white or pale grey and finely fibrous, often with a faint cortina-like ring zone created by a fleeting veil. The stem yellows slightly with age.

4. Pileipellis

   A cutis made up of hyphal elements mostly 15-45 x 3-8μm.

5. Spores

   Ellipsoidal, smooth, 4-6 x 3-4μm, with a hilar appendage; inamyloid.

6. Spore print

   White.

7. Odor and Taste

   Mealy taste and odor, becoming unpleasantly rancid when old.

8. Habitat & Ecological Role

   Mycorrhizal, in broad-leaf woodland, mainly with Beech, limes and oaks; occasionally in pine woodland.

9. Similar Species

   Tricholoma sciodes is usually greyer in appearance, often with a violet tinge to its cap surface, and its gill edges develop black speckles; it occurs in oak woodland; its spores are much broader than those of Tricholoma scalpturatum.

History

When Elias Magnus Fries described this mushroom scientifically in 1838 he established it basionym, giving it the name Agaricus scalpturatus. (In the early days of fungus taxonomy, most of the gilled mushrooms were included initially in the genus Agaricus, but the vast majority have since been relocated in other newer genera to leave on the 'true mushroom' in a more manageable Agaricus genus.) It was French mycologist Lucien Quelet who in an 1872 publication established the currently-accepted scientific name as Tricholoma scalpturatum.

The generic name Tricholoma means 'with hairs on the edge', which is true of only a minority of species in this genus. The specific epithet scalpturatum means scratched or engraved - a reference to the scales on the surface of the cap of this mushroom.

Synonyms

1. Agaricus chrysites Jungh. (1830)

2. Agaricus scalpturatus Fr. (1838)

3. Gyrophila argyracea var. chrysites (Jungh.) Quél. (1886)

4. Tricholoma argyraceum subsp. chrysites (Jungh.) Sacc. (1887)

5. Tricholoma argyraceum var. chrysites (Jungh.) Gillet (1874)

6. Tricholoma chrysites (Jungh.) Quél.

Photo sources:

Photo 1 - Author: User:Strobilomyces (CC BY-SA 2.5)

Photo 2 - Author: Strobilomyces (CC BY-SA 4.0)

Photo 3 - Author: Strobilomyces (CC BY-SA 3.0)

Photo 4 - Author: Jerzy Opioła (CC BY-SA 4.0)