Tricholoma orirubens

Description
Mushroom Identification
History
Synonyms

Description

Tricholoma orirubens is an edible gilled mushroom native to Europe. It has a dark gray or gray-brown cap with darker blackish scales, and a straight or undulating margin. The cap is conical with a slight boss before opening and flattening, eventually with either a boss or central depression. The thick gray gills are emarginate or adnate and widely spaced and turn red when bruised.

Widespread across Europe, Tricholoma orirubens is not common. It is rare in the Netherlands. Found singly or in small groups in deciduous and coniferous woodland in autumn, it prefers clayey or chalky soils. It is ectomycorrhizal.

Tricholoma orirubens can also form fairy rings. One found in Germany had a diameter of around 80 m (260 ft) and contained an estimated 10,000 mushrooms.

Common names: Lushing Tricholoma.

Mushroom Identification

Cap
4-9 (11) cm in diameter, fleshy, convex or conical, and hunched with the edge not twisted inwards, then flattened, bent and/or deepened in the shape of a funnel with a sharp hump in the middle. The surface of the cuticle, provided in youth with dark fibers arranged radially, is at first velvety, then sprinkled with exerted scales that break out a darker color. The original color is almost black, then changes, becoming gray-brown to almost brownish-black, with a darker center and a lighter edge, turning slightly yellow in old age.
Gills
Fragile, rather thin and relatively distant, often wavy, adherent, bulging at the foot (called: castle ditch) with edges initially smooth, then serrated, being at first whitish-gray which reddish by pressing, later pink or staining reddish.
Stem
4 to 8 (12) cm long and 1.2 to 2 cm wide, cylindrical, sometimes slightly bent, full, with a slightly thickened base, somewhat fibrous and without a ring. The whitish-gray to whitish bark, aged with reddish spots like lamellae, is smooth with a pattern of vertical brown fibers. At the base, it is blue-green or pale reddish with a white mycelium. After pressing, it fades to rust.
Flesh
Has a thickness of over 5mm in the center of the cap, being slightly fibrous in the leg and of a whitish color until pale yellowish or light cream-yellowish. The smell is pleasant, slightly floury and the taste is sweet-floury. It reddens after cutting, but only very hesitantly, only after several hours.
Microscopic Features
Ovoid spores, almost spherical, apical towards the tip, with a large drop, oily in the middle, hyaline (translucent) and non-amyloid (does not discolor with iodine reagents), having a size of 6-7 x 5-6 microns. Their powder is white. The basidia nailed with brooches and four (rarely two) sterigms each measure 25-30 x 6-7 microns. Cysts usually striking and sterile cells that can appear between the basidia and the hymen (fruit layer) are shorter, with rounded tips and pediculate. The unequal, cylindrical, sometimes swollen cuticle hyphae with a size of 20-56 x 6-16 (17) microns with nailed and septate end elements are similar to those of the cap meat of 18-50 x 5-15 microns. Intracellular pigments are inlaid and brown, but only at the top. Pileocysts (sterile elements on the surface of the cap) without brooches with a width of 4-7µm have cylindrical hyphae with finely inlaid walls and hyaline. Caulocysts (cysts located on the surface of the foot) are missing.
Chemical Reactions
The base of the foot is discolored with red formaldehyde, the lamellae with immediately red iron sulfate, and the meat with Guaiacum tincture slowly blue-green.

History

Tricholoma orirubens was described by French mycologist Lucien Quélet in 1873. The generic name derives from the Greek trichos/τριχος 'hair' and loma/λωμα 'hem', 'fringe' or 'border'. It lies within the section terrea within the subgenus Tricholoma within the genus Tricholoma.