This section is from the book "Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc.", by George Francis Atkinson. Also available from Amazon: Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc..
The genus Cortinarius is chiefly distinguished from the other genera of the ochre-spored agarics by the presence of a spider-weblike (arachnoid) veil which is separate from the cuticle of the pileus, that is, superficial. The gills are powdered by the spores, that is, the spores fall away with difficulty and thus give the gills a pulverulent appearance. The plants are fleshy and decay easily. It is necessary to have plants in the young as well as the old state to properly get at the characters, and the character of the veil is only seen in young or half developed specimens. The species are to be distinguished from other ochre-spored agarics with a cobwebby veil by the fact that the veil in Cortinarius is superficial and the gills powdery. The number of species is very large, and they are difficult to determine. They mostly occur in northern countries and in the autumn or late summer; some species, however, occur during early summer. Peck, 23d Report, N. Y. State Mus., p. 105-112, describes 21 species.
Cortinarius (Inoloma) violaceus (L.) Fr. Edible. - This species is known by the violet or dark violet color which pervades all parts of the plant. The plants are 8-10 cm. high, the pileus 7-15 cm. broad, and the stem is bulbous, 6-8 mm. in thickness. The veil is single. It occurs in woods and open places during late summer and in the autumn. The flesh of the plant is also violet, and this color is imparted to the liquid when the plant is cooked. The flavor is said to be something like that of Agaricus campestris.
Cortinarius (Myxacium) collinitus (Pers.) Fr. Edible. - This is known as the smeared cortinarius because of the abundant glutinous substance with which the plant is smeared during moist or wet weather, It grows in woods. The plants are 7-10 cm. high, the cap 5-8 cm. in diameter, and the stem is 8-12 mm. in thickness. It is usually known by the smooth, even, tawny cap, the great abundance of slimy substance covering the entire plant when moist, and when dry the cracking of the gluten on the stem into annular'patches.
The pileus is convex to expanded, smooth, even, glutinous when wet, shining when dry, tawny. The gills are adnate with a peculiar bluish gray tinge when young, and clay color to cinnamon when old. The spores are nearly elliptical, and 12-15 x 6-7 µ. The stem is cylindrical, even, and with patches of the cracked gluten when dry.
Cortinarius (Dermocybe) cinnamomeus (L.) Fr. Edible. - The cinnamon cortinarius is so called because of the cinnamon color of the entire plant, especially of the cap and stem. It grows in the woods during summer and autumn. It is a very pretty plant, and varies from 5-8 cm. high, the cap from 2-10 cm. broad, and the stem 4-6 mm. in thickness. The pileus is conic, or convex, and nearly expanded, sometimes nearly plane, and again with a prominent blunt or conic umbo. Sometimes the pileus is abruptly bent downward near the margin as shown in the plants in Fig. 155, giving the appearance of a "hip-roof." The surface is smooth, silky, with innate fibrils. Sometimes there are cinnabar stains on parts of the pileus, and often there are concentric rows of scales near the margin. The flesh is light yellowish and with stains of cinnabar. The gills are adnate, slightly sinuate, and decurrent by a tooth, easily separating from the stem, rather crowded, slightly ventricose. The color of the gills varies greatly; sometimes they are the same color as the pileus, sometimes reddish brown, sometimes blood red color, etc. This latter form is a very pretty plant, and is var. semi-sanguineus Fr. Figure 155 is from plants (No. 2883 C. U. herbarium) collected at Ithaca. The species is widely distributed in this country as well as in Europe.
Figure 155
Cortinarius cinnamomeus var. semi-sanguineus. Cap and stem cinnamon, gills blood red color (natural size). Copyright.
Plate 50, Figure 156
Cortinarius ochroleucus. Entire plant pale ochre color, gills later ochre yellow (natural size). Copyright.
Plate 51, Figure 157
Cortinarius ochroleucus. Colors same as in Figure 156, this represents older plants.
Cortinarius (Dermocybe) ochroleucus (Schaeff.) Fr. - This is a very beautiful plant because of the soft, silky appearance of the surface of pileus and stem, and the delicate yellowish white color. It occurs in woods, on the ground among decaying leaves. The plants are 4-12 cm. high, the cap 4-7 cm. broad, and the stem above is 6-10 mm. in thickness, and below from 2-3 cm. in thickness.
The pileus is convex to nearly expanded, and sometimes a little depressed, usually, however, remaining convex at the top. It is dry, on the center finely tomentose to minutely squamulose, sometimes the scales splitting up into concentric rows around the cap. The cap is fleshy at the center, and thin at the margin, the color is from cream buff to buff, darker on the center. The gills are sinuate or adnate, slightly broader in the middle (ventricose) in age, pale at first, then becoming ochre yellow, and darker when the plant dries. The spores are tawny in mass, oval, elliptical, minutely tuberculate when mature, 6-9 x 4-6 µ. The stem is clavate, pale cream buff in color, solid, becoming irregularly fistulose in age, bulbous or somewhat ventricose below, the bulb often large and abrupt, 1.5-3 cm. in diameter. The veil is prominent and attached to the upper part of the stem, the abundant threads attached over an area 1 cm. in extent and forming a beautiful cortina of the same color as the pileus and stem, but becoming tawny when the spores fall on it. The stem varies considerably in length and shape, being rarely ventricose, and then only at the base; the bulbous forms predominate and the bulb is often very large.
Figures 156, 157 are from plants (No. 3674 C. U. herbarium) collected at Blowing Rock, N. C, during September, 1899.
 
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