The species was first described scientifically by American mycologist Charles Horton Peck in 1886, who made the type collections in Day, New York.

[5] 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.

The closely spaced gills are white, cream, or pale yellow in color, and have an adnate attachment to the stem.

[4] An edible mushroom,[6] R. crustosa has no distinguishing odor, and a taste ranging from mild to slightly acrid.

Other greenish Russulas, including R. subgraminicolor, R. aeruginea, and R. variata, can be most readily distinguished by their non-cracking cap surfaces.