Russula crustosa

Russula crustosa
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Order:	Russulales
Family:	Russulaceae
Genus:	Russula
Species:	R. crustosa
Binomial name
Russula crustosa Peck (1886)

Russula crustosa, commonly known as the crusty russula, is a species of fungus in the family Russulaceae. It is found in Asia and North America.

The species was first described scientifically by American mycologist Charles Horton Peck in 1886, who made the type collections in Day, New York. It is classified in the subsection Virescentinae of the genus Russula. The specific epithet crustosa means "with a rind".Common names for the species include "crusty Russula", "green quilt Russula", and "encrusted Russula".

The fruit bodies have caps that are initially convex before flattening out in age, often developing a central depression, and measure 5–12.5 cm (2.0–4.9 in) in diameter. In maturity, the dry cap surface breaks up into greenish patches around the margin. The margin of the cap has radial grooves that match the gills on the underside. The closely spaced gills are white, cream, or pale yellow in color, and have an adnate attachment to the stem. Measuring 3–9 cm (1.2–3.5 in) long by 1.2–2.5 cm (0.5–1.0 in) thick, the stem is white to pale yellow, and becomes hollow in age. The flesh is hard and compact (when young), and whitish. The spore print is pale buff, and the spores are elliptic in shape, and somewhat warted with a few fine interconnecting lines. They are hyaline (translucent), amyloid, and measure 6–9 by 5.5–7 µm.

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