Nigricans means blackish.
The pileus is two to four inches broad, dark grayish-brown, black with advancing age, fleshy, compact, flesh turning red when bruised or convex, flattened, then depressed, at length funnel-shaped, margin entire, without striate, margin at first incurved, young specimens are slightly viscid when moist, even, without a separable pellicle; whitish at first, soon sooty olive, at length becoming broken up into scales and black; flesh firm and white, becoming reddish when broken.
The gills are rounded behind, slightly adnexed, thick, distant, broad, unequal, the shorter ones sometimes very scanty, forked, reddening when touched.
The stem is rather short, thick, solid, equal, pallid when young, then black. The spores are subglobose, rough, 8–9µ.
The plant is quite compact, inodorous, becoming entirely black with age. It is easily distinguished from R. adusta by the flesh becoming reddish when bruised, and by the much thicker, and more distant gills. It is very close to R. densifolia but differs from it in that its gills are more distant and because of its mild taste.
I am pleased to present to my readers, in Figure 146, a photograph of a plant which grew in Sweden in the locality where Prof. Fries did his great work in fungal study and research. It is a typical specimen of this species. It was gathered and photographed by Mr. C. G. Lloyd.
It is found from June to October. Not poisonous, but not good.
Russula fœtens. Fr.
The Fetid Russula. Not Edible.