AMANITOPSIS Roze.
This genus has white spores, and a volva, but the annulus and inner veil are wanting. In other respects it agrees with Amanita. It is considered as a sub-genus of Amanita by some.
Plate 22, Figure 76.—Amanita solitaria. Three plants, 3/4 natural size. Copyright.
Amanitopsis vaginata (Bull.) Roz. Edible.—The sheathed amanitopsis, A. vaginata, is a quite common and widely distributed plant in woods. It is well named since the prominent volva forms a large sheath to the cylindrical base of the stem. The plant occurs in several forms, a gray or mouse colored form, and a brownish or fulvous form, and sometimes nearly white. These forms are recognized by some as varieties, and by others as species. The plants are 8–15 cm. high, the caps 3–7 cm. broad, and the stems 5–8 mm. in thickness.
Plate 23, Figure 77.—Amanitopsis vaginata. Tawny form (natural size). Copyright.
The pileus is from ovate to bell-shaped, then convex and expanded, smooth, rarely with fragments of the volva on the surface. The margin is thin and marked by deep furrows and ridges, so that it is deeply striate, or the terms sulcate or pectinate sulcate are used to express the character of the margin. The term pectinate sulcate is employed on account of a series of small elevations on the ridges, giving them a pectinate, or comb-like, appearance. The color varies from gray to mouse color, brown, or ochraceous brown. The flesh is white. The gills are white or nearly so, and free. The spores are globose, 7–10 µ in diameter. The stem is cylindrical, even, or slightly tapering upward, hollow or stuffed, not bulbous, smooth, or with mealy particles or prominent floccose scales. These scales are formed by the separation of the edges of the gills from the surface of the stem, to which they are closely applied before the pileus begins to expand. Threads of mycelium growing from the edge of the lamellæ and from the stem intermingle. When the pileus expands these are torn asunder, or by their pull tear up the outer surface of the stem. The volva forms a prominent sheath which is usually quite soft and easily collapses (Fig. [77]).
The entire plant is very brittle and fragile. It is considered an excellent one for food. I often eat it raw when collecting.
Authors differ as to the number of species recognized in the plant as described above. Secretan recognized as many as ten species. The two prominent color forms are quite often recognized as two species, or by others as varieties; the gray or mouse colored form as A. livida Pers., and the tawny form as A. spadicea Pers. According to Fries and others the livida appears earlier in the season than spadicea, and this fact is recognized by some as entitling the two to specific rank. Plowright (Trans. Brit. Mycol. Soc., p. 40, 1897–98) points out that in European forms of spadicea there is a second volva inside the outer, and in livida there are "folds or wrinkles of considerable size on the inner surface of the volva." He thinks the two entitled to specific rank. At Ithaca and in the mountains of North Carolina I have found both forms appearing at the same season, and thus far have been unable to detect the differences noted by Plowright in the volva. But I have never found intergrading color forms, and have not yet satisfied myself as to whether or not the two should be entitled to specific rank.
Some of the other species of Amanitopsis found in this country are A. nivalis Grev., an entirely white plant regarded by some as only a white form of A. vaginata. Another white plant is A. volvata Pk., which has elliptical spores, and is striate on the margin instead of sulcate.
Figure 78.—Amanitopsis farinosa. Cap grayish (natural size). Copyright.
Amanitopsis farinosa Schw.—The mealy agaric, or powdery amanita, is a pretty little species. It was first collected and described from North Carolina by de Schweinitz (Synop. fung. Car. No. 552, 1822), and the specimens illustrated in Fig. [78] were collected by me at Blowing Rock, N. C., during September, 1899. Peck has given in the 33rd Report N. Y. State Mus., p. 49, an excellent description of the plant, though it often exceeds somewhat the height given by him. It ranges from 5–8 or 10 cm. high, the cap from 2–3 cm. broad, and the stem 3–6 mm. in thickness.
The pileus is from subglobose to convex and expanded, becoming nearly plane or even depressed by the elevation of the margin in old specimens. The color is gray or grayish brown, or mouse colored. The pileus is thin, and deeply striate on the margin, covered with a grayish floccose, powdery or mealy substance, the remnant of the evanescent volva. This substance is denser at the center and is easily rubbed off. The gills are white and free from the stem. The spores are subglobose and ovate to elliptical, 6–7 µ long. The stem is cylindrical, even, hollow or stuffed, whitish or gray and very slightly enlarged at the base into a small rounded bulb which is quite constant and characteristic, and at first is covered on its upper margin by the floccose matter from the volva.
Plate 24, Figure 79.—Lepiota naucina. Entirely white (natural size).
At Blowing Rock the plants occurred in sandy soil by roadsides or in open woods. In habit it resembles strikingly forms of Amanitopsis vaginata, but the volva is entirely different (Fig. [78]). Although A. vaginata was common in the same locality, I searched in vain for intermediate forms which I thought might be found. Sometimes the floccose matter would cling together more or less, and portions of it remained as patches on the lower part of the stem, while depauperate forms of A. vaginata would have a somewhat reduced volva, but in no case did I find intermediate stages between the two kinds of volva.