The pileus is three to five inches broad, compact, at first convex, and umbilicate, then expanded and centrally depressed or subinfundibuliform, obsoletely tomentose or glabrous except on the margin, white or whitish, often varied with yellowish or sordid strains, the margin at first involute and clothed with a dense, soft cottony tomentum, then spreading or elevated and more or less fibrillose.
The gills are rather broad, distant or subdistant, adnate or decurrent, some of them, forked, whitish, becoming cream-colored.
The stem is one to three inches long, equal or narrowed downward, solid, pruinose-pubescent, white. Spores are white, 9–12.7µ. Milk white, taste acrid.
This plant delights in woods and open groves, especially under coniferous trees. It is a large, meaty, acrid white species, with a thick, soft, cottony tomentum on the margin of the pileus of the young plant.
The specimen photographed was sent me from Massachusetts by Mrs. Blackford. It grows in July, August and September. Its sharp acridity is lost in cooking, but like all acrid Lactarius it is coarse and not very good.
Lactarius indigo. (Schw.) Fr.
Figure 130.—Lactarius indigo. One-third natural size. Entire plant indigo blue.