Stems low, herbaceous, with an acid juice and alternate compound leaves. Flowers regular, symmetrical, hypogynous, 5-merous. Sepals persistent, imbricated; petals convolute in aestivation. Stamens 10, somewhat monadelphous, those opposite the petals longest Styles 5, separate; capsule 5-celled, several-seeded; seeds albuminous. (Illust. in Figs. 59. 64, 585.)
Genera 7, species 328, inhabiting the hot and the temperate regions. The most noticeable property of the Order is the sour juice, containing oxalic acid. Several species are cultivated for the beauty of their flowers.
OXALIS, L. Wood Sorrel. (Gr. sour.) Sepals 5, distinct or united at base; petals much longer than the calyx; styles 5, capitate; capsule oblong or sub-globous: carpels 5, 1 to several-seeded.- Mostly , with trifoliate lvs. and inversely heart-shaped leaflets.
1 O. Acetosella L. Acaulescent; scope longer than the leaves, 1- flowered; 1fta broad-obcordate with rounded lobes; sty. as long as the inner stamens; rt. dentate, scaly. - Woods and shady places, Can. and Northern States. Lvs. palmately 3-foliate, on long, weak stalks, purplish beneath. Ped. longer than the leaves, each with a nodding, scentless flower whose petals are white, yellowish at the base, delicately veined with purple. The whole plant has an agreeable acid taste. Jn.
2 O. violacea L. Acaulescent, smooth; scape umbeliferous; pedicels, subpubes-cent; fls. nodding; tips of the calyx fleshy; sty. shorter than the outer stamens. - An elegant species in rocky woods, etc., throughout the U. S. Bulb scaly. Scape nearly twice longer than the leaves, 5 to 8' high. Lvs. palmately 3-foliate, sometimes none; 1fts. nearly twice as wide as long, with a very shallow sinus at the very broad apex. Umbels of 3 to 9 drooping flowers. Petals large, violet-colored, striate. May.
3 O. atricta L. Caulescent; st. branching; ped. umbeliferous, longer than the petioles; sty. as long as the inner stamens. - Fields, U. S. and Can., common. It varies in size from 3 to 12', according to the soil. St leafy, round, smooth. succulent Lvs. palmately 3-foliate, numerous, scattered, on long stalks. Umbels on long, axillary stalks, mostly much longer than the petioles. Fls. small, yellow, appearing all summer. Capsules sparingly hirsute, with spreading hairs.- When the plant is unsupported, it is more or less decumbent and is the variety
β. corniculata (0. corniculata L). - Obs. The species (nearly 300 in number) are all pretty, and many from Europe and Africa are becoming rather common in cultivation.