Low fleshy glabrous perennial herbs, with erect stems. Leaves mostly basal, long-petioled, reniform or orbicular, cordate, palmately nerved, with cylindric ocreae. Flowers perfect, small, green, in terminal panicled racemes. Calyx unequally 4-parted, the outer segments smaller than the inner; stamens 6, included; filaments subulate. Ovary 1-celled; ovule solitary; style short, 2-parted, its branches divergent; stigmas fimbriate, persistent on the large wings of the fruit. Achene-body ovate, lenticular, broadly winged. Embryo straight, borne in the centre of the endosperm. [Greek, sour, from the acid leaves.]

Two known species, the following typical; one in the Himalayas.

4 Oxyria Hill Veg Syst 10 24 1765 1614

1. Oxyria Digyna (L.) Hill. Mountain Sorrel

Fig. 1614

Rumex digyttus L. Sp. PI. 337. 1753. O. digyna Hill, Hort. Kew. 158. 1768. Oxyria reniformis Hook. Fl. Scot. 111. 1821.

Rootstock large, chaffy; stems scape-like, simple or sparingly branched, leafless or nearly so, 2'-12' tall. Leaves reniform or orbicular-reniform, 1/2'-1 1/2' wide, undulate, sometimes emarginate at the apex, the basal long-petioled; ocreae oblique, loose, those on the stem bearing flowers; racemes many-flowered; flowers slender-pedicelled; segments oblong, the inner erect, the outer reflexed in fruit; achene-body pointed, smooth, surrounded by a broad membranous wing.

Greenland and Labrador to Alaska, south to the White Mountains of New Hampshire and in the Rocky Mountains to Colorado and to California. Also in northern Europe and Asia. Sour dock. July-Sept.