Flower very irregular. Calyx persistent, of 5 sepals, of which 3 (the upper and the 2 lower) are small and often greenish, while the two lateral or inner (called _wings_) are much larger, and colored like the petals. Petals 3, hypogynous, connected with each other and with the stamen-tube, the middle (lower) one keel-shaped and often crested on the back. Stamens 6 or 8; their filaments united below into a split sheath, or into 2 sets, cohering more or less with the petals, free above; anthers 1-celled, often cup-shaped, opening by a hole or broad chink at the apex. Ovary 2-celled, with a single anatropous ovule pendulous in each cell; style prolonged and curved; stigma various. Fruit a small, loculicidal 2-seeded pod, usually rounded and notched at the apex, much flattened contrary to the very narrow partition. Seeds carunculate. Embryo large, straight, with flat and broad cotyledons, in scanty albumen.--Bitter plants (low herbs in temperate regions), with simple entire often dotted leaves, and no stipules; sometimes (as in the first two species) bearing cleistogamous flowers next the ground. (An old name composed of πολύς, _much_, and γάλα, _milk_, from a fancied property of its increasing this secretion.) [*] _Perennial or biennial; flowers purple or white; leaves alternate._ [+] _Flowers showy, rose-purple, conspicuously crested; also bearing inconspicuous colorless cleistogamous flowers on subterranean branches._ 1. P. paucifòlia, Willd. _Perennial_; flowering stems short (3--4´ high), from long slender prostrate or subterranean shoots, which also bear concealed fertile flowers; lower leaves small and scale-like, scattered, the _upper ovate, petioled, crowded_ at the summit; _flowers 1--3, large_, peduncled; wings obovate, rather shorter than the fringe-crested keel; stamens 6; caruncle of 2 or 3 awl-shaped lobes longer than the seed.--Woods, in light soil, N. Eng. to Minn., Ill., and southward along the Alleghanies. May.--A delicate plant, with very handsome flowers, 9´´ long, rose-purple, or rarely pure white. Sometimes called _Flowering Wintergreen_, but more appropriately FRINGED POLYGALA. 2. P. polýgama, Walt. Stems numerous from the _biennial_ root, mostly simple, ascending, very leafy (6--9´ high); _leaves oblanceolate or oblong_; terminal _raceme loosely many-flowered_, the broadly obovate wings longer than the keel; stamens 8; radical flowers racemed on short subterranean runners; lobes of the caruncle 2, scale-like, shorter than the seed.--Dry sandy soil; common. July. [+][+] _Flowers white, in a solitary close spike; none cleistogamous._ 3. P. Sénega, L. (SENECA SNAKEROOT.) Stems several from thick and hard knotty rootstocks, simple (6--12´ high); leaves lanceolate or oblong-lanceolate, with rough margins; wings round-obovate, concave; crest short; caruncle nearly as long as the seed.--Rocky soil, W. New Eng. to Minn., and southward. May, June.