Studies of American Fungi. Mushrooms, Edible, Poisonous, etc. George Francis Atkinson

Studies of American Fungi. Mushrooms, Edible, Poisonous, etc - George Francis Atkinson


Скачать книгу
covering the upper part of the bulb and the young cap. As the stem elongates and the pileus enlarges and expands, the volva is torn into areolate patches. The lower patches, those adjoining the margin of the cap and the upper part of the bulb, are separated in a more or less concentric manner. One or more of them lie on the upper part of the bulb, forming the "limb" of the "ocreate" volva. Others lie around the margin of the pileus. Sometimes an annular one bordering the pileus and bulb is left clinging part way up on the stem, as shown in Fig. 66. The concentric arrangement on the pileus is sometimes shown for a considerable time, as in Fig. 67, the elongated areas being present in greater number at this age of the pileus. However, as the pileus expands more, these are separated into smaller areas and their connection with the surface of the pileus becomes less firm.

      The formation of the veil and annulus can be easily followed in these figures. The margin of the cap in the button stage is firmly connected with the outer layer of the stem at its lower end. This probably occurs by the intermingling growth of the threads from the lower end of the stem and the margin of the cap, while the edges of the gills are quite free from the stem. Now as the stem elongates and the cap expands the veil is "ripped" up from the outer part of the stem. This is very clearly shown in Fig. 66, especially where two strips on the stem have become disconnected from the margin of the cap and are therefore left in position on the outside of the stem.

      This species is related to A. excelsa Fr., which is said to have a superior ring.

      Plate 16, Figure 67.—Amanita velatipes. The right-hand plant shows how the veil is ripped up from the stem and also shows the transversely elongate scales on the cap. For details see text (natural size). Copyright.

      Amanita cothurnata Atkinson. Probably Poisonous.—The booted amanita, Amanita cothurnata, I have found in two different years in the Blue Ridge mountains at Blowing Rock, N. C., once in 1888, during the first week of September, and again during the three first weeks in September, 1899. It occurs sparingly during the first week or so of September, and during the middle of the month is very abundant. The species seems to be clearly distinct from other species of Amanita, and there are certain characters so persistent as to make it easily recognizable. It ranges in height from 7–12 cm. and the caps are 3–7 cm. or more broad, while the stems are 4–10 mm. in thickness. The entire plant is usually white, but in some specimens the cap has a tinge of citron yellow, or in others tawny olive, in the center.

      Plate 17, Figure 68.—Amanita cothurnata. Different stages of development; for details see text. Entire plant white, sometimes tinge of umber at center of cap, and rarely slight tinge of lemon-yellow at center (natural size). Copyright.

      The pileus is fleshy, and passes, in its development, from nearly globose to hemispherical, convex, expanded, and when specimens are very old sometimes the margin is elevated. It is usually white, though specimens are found with a tinge of citron yellow in the center, or of tawny olive in the center of other specimens. The pileus is viscid, strongly so when moist. It is finely striate on the margin, and covered with numerous, white, floccose scales from the upper half of the volva, forming more or less dense patches, which may wash off in heavy rains. The gills are rounded next the stem, and quite remote from it. The edge of the gills is often eroded or frazzly from the torn out threads with which they were loosely connected to the upper side of the veil in the young or button stage. The spores are globose or nearly so, with a large "nucleus" nearly filling the spore.

      Figure 69.—Amanita cothurnata. Different stages opening up of plant, the two center ones showing veil being ripped from stem, but veil narrow. The right-hand illustration has been scratched transversely, these marks not being characteristic of the plant (natural size). Copyright.

      The stem is cylindrical, even, and expanded below into quite a large oval bulb, the stem just above the bulb being margined by a close fitting roll of the volva, and the upper edge of this presenting the appearance of having been sewed at the top like the rolled edge of a garment or buskin. The surface of the stem is minutely floccose scaly or strongly so, and decidedly hollow even from a very young stage, or sometimes when young with loose threads in the cavity.

      Figures 68–70, from plants (No. 3715, C. U. herbarium) collected at Blowing Rock, N. C., during September, 1899, illustrate certain of the features in the form and development of this plant.

      Figure 70.—Amanita cothurnata. Two plants in section showing clearly hollow stem, veil attachment, etc. (natural size). Copyright.

      In Amanita frostiana the remains of the volva sometimes form a similar collar, but not so stout, on the base of the stem. The variations in A. frostiana where the stem, annulus and gills are white might suggest that there is a close relationship between A. frostiana and A. cothurnata, and that the latter is only a form of the former. From a careful study of the two plants growing side by side the evidence is convincing that the two are distinct. Amanita frostiana occurs also at Blowing Rock, appearing earlier in the season than A. cothurnata, and also being contemporary with it. A. frostiana is more variable, not nearly so viscid, nor nearly so abundant, the stem is solid or stuffed, the annulus is more frail and evolved from the stem in a different manner. The volva does not leave such a constant and well defined roll where it separated on the stem transversely, and the pileus is yellow or orange. When A. cothurnata is yellowish at all it is a different tint of yellow and then only a tinge of yellow at the center. Albino or faded forms of A. frostiana might occur, but we would not expect them to appear at a definite season of the year in great abundance while the normal form, showing no intergrading specimens in the same locality, continued to appear in the same abundance and with the same characters as before. The dried plants of A. cothurnata are apt to become tinged with yellow on the gills, the upper part of the stem and upper part of the annulus during the processes of drying, but the pileus does not change in like manner, nor do these plants show traces of yellow on these parts when fresh. The spores are also decidedly different, though the shape and size do not differ to any great extent. In A. frostiana and the pale forms of the species the spores are nearly globose or oval, rarely with a tendency to become elliptical, but the content is quite constantly finely granular, while the spores of A. cothurnata are perhaps more constantly globose or nearly so, but the spore is nearly filled with a highly refractive oil globule or "nucleus." The pileus of A. frostiana is also thinner than that of A. cothurnata. It is nearer, in some respects, to specimens of Amanita pantherina received from Bresadola, of Austria-Hungary.

      Figure 71.—Amanita spreta. The two outside plants show the free limb of the volva lying close against the stem (natural size, often larger). Copyright.

      Amanita spreta Pk. Said to be Poisonous.—According to Peck this species grows in open or bushy places. The specimens illustrated in Fig. 71 grew in sandy ground by the roadside near trees in the edge of an open field at Blowing Rock, N. C., and others were found in a grove. The plants are 10–15 cm. high, the caps 6–12 cm. broad, and the stems 8–12 mm. in thickness. The pileus is convex to expanded, gray or light drab, and darker on the center, or according to Dr. Peck it may be white. It is smooth, or with only a few remnants of the volva, striate on the margin, and 1—.5 cm. thick at the center. The gills are white, adnexed, that is they reach the


Скачать книгу