National Geographic : 1920 May
402 THE NATIONAL GEOGRAPHIC MAGAZINE Photograph by A. G . and B. Leeper THE OYSTER MUSI[ROOMt (Pieurotius ostreatus). EDIBLE The name of the luscious bivalve was given this species because of a fancied similarity in appearance. The plants may be found from June until late in the Autumn, growing on deciduous trees. About one-third natural size. If one has discovered one or more trees that bear Pleuroti, it is a good plan to water the spots from which specimens have been taken. In this way the plants may be "cultivated," as new "fruit" will appear in a week or two. When specimens are brought indoors and placed in a sunny nook, away from drafts, the interesting phenomenon of spore-discharge may be watched. Like twisting, curling spirals of smoke from the burning end of a cigar, the fine spore-rain drifts off into space in quest of tree wounds where it may lodge and start a mycelium that in turn will produce more Pleuroti. Related species and poisonous species are sometimes eaten in place of it, though Agari cus camnpester is so well marked that it is in conceivable how poisonous species, especially Amanitas, can be eaten by mistake. A mere glance at the illustrations of the common mushroom and those of the Amanitas (see Plates II, V, X, XV, and XVI) ought to prove instructive, even to the most superficially observing, and, if in addition the descriptions be compared, wide differences will at once be come apparent. To call attention to a few: Agaricus campester has a squattier appear ance; lacks a bag, or volva; has pink gills that turn to a chocolate brown, and never grows in woods or forests, preferring rich, well-ma nured ground, such as old pastures, where horses are turned loose. The Amanitas rarely occur anywhere except in woods, or in places where woods have re cently stood, such as lawns in new suburbs; throw down from their gills a white spore powder, and have, in addition to the ring, a more or less pronounced volva at the usually bulhous base of the stem (for figures of the various forms of the Volva, or Death-cup, see Nature's Danger Signals, page 389). THE FIELD, OR HORSE MUSHROOM (Agaricus arvensis). Edible (See Color Plate I) This coarse and heavy species is edible only when young and tender. Some epicures object to its anise-like odor. The distinguishing fea tures are: its large size (breadth of cap some times more than a foot); peculiar ashy-pink tint of the young gills; large, thick, double ring (the lower one split radiately); the bulb ous stem, and the tendency to turn yellow on the slightest bruise. It is not so choice in its habitats as the com mon mushroom, growing in cultivated fields, grassy pastures, in waste places, under old hedges, and occasionally near trees, and in the borders of thin woods. It should be sought from July to September. Occasionally it forms huge fairy-rings (see page 397).