The species of Russula are very characteristic, and the genus is easily recognized in most cases after a little experience. In the very brittle texture of the plants the genus resembles Lactarius, and many of them are more brittle than the species of this genus. A section of the pileus shows under the microscope a similar vesicular condition, that is the grouping of large rounded cells together, with threads between. But the species of Russula are at once separated from those of Lactarius by the absence of a juice which exudes in drops from bruised parts of Lactarius. While some of the species are white and others have dull or sombre colors, many of the species of Russula have bright, or even brilliant colors, as red, purple, violet, pink, blue, yellow, green. In determining many of the species, however, it is necessary to know the taste, whether mild, bitter, acrid, etc., and in this respect the genus again resembles Lactarius. The color of the gills as well as the color of the spores in mass should also be determined. The genus is quite a large one, and the American species are not well known, the genus being a difficult one. In Jour. Myco-log., 5: 58-64, 1889, the characters of the tribes of Russula with descriptions of 25 species are quoted from Stevenson, with notes on their distribution in N. A. by MacAdam.

Russula alutacea Fr. Edible. - This handsome Russula differs from the others described here in the color of the gills and spores. The plant is common and occurs in mixed woods during the summer and early autumn. It is 5-10 cm. high, the cap 5-12 cm. broad, and the stem 1.5-2.5 cm. in thickness.

The pileus is fleshy, oval to bell-shaped, becoming plane, and sometimes umbilicate. It is red or blood red in color, sometimes purple, and becoming pale in age, especially at the center. It is viscid when moist, the margin thin and striate-tuberculate. The gills are free from the stem, stout, broad, first white, becoming yellow, and in age ochraceous. The gills are all of the same length, not crowded, and they are connected by vein-like elevations over the surface. The stem is stout, solid, even, white, portions of the stem are red, sometimes purple.

The taste is mild, and the plant is regarded as one of the very good ones for food.

Russula lepida Fr. Edible. - This elegant Russula occurs in birch woods or in mixed woods during late summer and autumn. It is 5-8 cm. high, the cap 6-8 cm. broad, and the stem 1-2 cm. in thickness.

The pileus is fleshy, convex, then expanded, obtuse, not shining, deep red, becoming pale in age, often whitish at the center, silky, in age the surface cracking, the margin blunt and not striate. The gills are rounded next the stem, thick, rather crowded, and sometimes forked, white, sometimes red on the edge near the margin of the pileus. The gills are often connected by vein-like elevations over the surface. The stem is equal, white or rose color. The taste is mild.

Russula virescens (Schaeff.) Fr. Edible. - This plant grows on the ground in woods or in grassy places in groves from July to September. The stem is short, 2-7 cm. long x 1-2 cm. thick, and the cap is 5-10 cm. broad. The plant is well known by the green color of the pileus and by the surface of the pileus being separated into numerous, quite regular, somewhat angular areas or patches, where the green color is more pronounced.

The pileus is first rounded, then convex and expanded, and when old somewhat depressed in the center. It is quite firm, dry, greenish, and the surface with numerous angular floccose areas or patches of usually a deeper green. Sometimes the pileus is said to be tinged with yellow. The gills are adnate, nearly free from the stem, and crowded. The stem is white and firm.

The greenish Russula, Russula virescens, like a number of other plants, has long been recommended for food, both in Europe and in this country. There are several species of Russula in which the pileus is green, but this species is readily distinguished from them by the greenish floccose patches on the surface of the pileus. Russula furcata is a common species in similar situations, with forked gills, and the cap very variable in color, sometimes reddish, purple, purple brown, or in one form green. I know of the Russula furcata having been eaten in rather small quantities, and while in this case no harm resulted the taste was not agreeable.

Plate 40.

Fig. 1. - Russula virescens.

Fig. 2. - R. alutacea.

Fig. 3. - R. lepida.

Fig. 4. - R. emetica.

Fig. 5. - Yellow Russula.

Fig. 6. - R. adusta. Copyright 1900.

Russula fragilis (Pers.) Fr. - This plant is very common in damp woods, or during wet weather from July to September. It is a small plant and very fragile, as its name suggests, much more so than most other species. It is 2-4 cm. high, the cap 2-5 cm. broad, and the stem about 1 cm. in thickness.

The pileus is convex, sometimes slightly umbonate, then plane, and in age somewhat depressed. The cuticle peels off very easily. The color is often a bright red, or pink, sometimes purple or violet, and becomes paler in age. It is somewhat viscid when moist, and the margin is very thin and strongly striate and tuberculate, i. e., the ridges between the marginal furrows are tuberculate. The gills are lightly adnexed, thin, crowded, broad, all of the same length, white. The stem is usually white, sometimes more or less pink colored, spongy within, becoming hollow. The taste is very acrid.

Russula emetica Fr. Poisonous. - This Russula has a very wide distribution and occurs on the ground in woods or open places during summer and autumn. It is a beautiful species and very fragile. The plants are 5-10 cm. high, the cap 5-10 cm. broad, and the stem 1-2 cm. in thickness. The pileus is oval to bell-shaped when young, becoming plane, and in age depressed. It is smooth, shining, the margin furrowed and tuberculate. The color is from pink or rosy when young to dark red when older, and fading to tawny or sometimes yellowish in age. The cuticle is easily separable as in R. fragilis, the flesh white, but reddish just beneath the cuticle. The gills are nearly free, broad, not crowded, white. The stem is stout, spongy within, white or reddish, fragile when old.

The plant is very acrid to the taste and is said to be poisonous, and to act as an emetic.

Russula adusta (Pers.) Fr. - This plant occurs on the ground in woods during late summer and in autumn. It is 3-6 cm. high, the cap 5-15 cm. broad, and the stem is 1-1.5 cm. in thickness.

The pileus is fleshy, firm, convex, depressed at the center, and when old more or less funnel-shaped from the upturning of the margin, which is at first incurved and smooth. It varies from white to gray and smoky color. The gills are adnate, or decurrent, thin, crowded, of unequal lengths, white, then becoming dark. The stem is colored like the pileus. The entire plant becomes darker in drying, sometimes almost black. It is near Russula nigricans, but is smaller, and does not have a red juice as R. nigricans has.