Pileus
(from pileus, a cap). The name given to the broad, expanded part in Mushrooms and allied groups of the larger Fungi. It is very frequently, e.g., in the common Mushroom, shaped like an inverted saucer, or a shallow skull-cap but shows a considerable diversity of shape in different species; e.g., in Marasmius oreades and Hydnum repandum It is usually fixed by the middle of its lower surface, as in all the examples quoted, to the stop of a stalk; but in a good many Fungi that possess a Pileus, the stalk is fixed to one side (e.g., in many species of Polyporus), and others want it altogether. The upper surface of the Pileus is usually covered with a skin or coat, which in many species is slimy, but in some is scaly, in others hairy, &c. The Pileus bears generally, on its lower surface, the spore-producing surface, or hymenium--in some genera, in the form of gills; in others, like tubes or fleshy teeth (see Mushrooms). The Pileus and stalk together form the hymenophore. PILOCARPUS from pilos, a cap, and karpos, a fruit; referring to the shape of the berries). ORD. Rutaceae. A genus comprising about five species of stove shrubs, natives of tropical America and the West Indies. Flowers green or purple, gland-dotted; calyx short, almost entire, or four or five-toothed; petals four or five, triangular; racemes or spikes simple, terminal or axillary. Leaves petiolate, opposite or alternate, or ternately whorled, one to three-foliolate or impari-pinnate, coriaceous or membranous, entire, pellucid-dotted. For culture, see Chloroxylon.
P. pennatifolius (feather-leaved). fl. purple, in crowded racemes, 18in. long; petals thick, lanceolate. l. alternate, impari-pinnate; leaflets two or three-jugate, elliptic or oblanceolate, the margins obsoletely revolute, pellucid-dotted. h. 6ft. Brazil. (B. M. Pl. 48; L. J. F. iii. 263.) This is one of the plants which furnishes the Jaborandi of commerce, an energetic diaphoretic and sialogogue.
