BUCKWHEAT FAMILY. 553 
4. OXYRIA Hill, Veg. Syst. 10:24. 1765. 
Low fleshy glabrous perennial herbs, with slender erect stems. eaves 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 short, subulate, glabrous; an- 
thers oblong. Ovary 1-celled; ovule solitary; style short, 2-parted, its branches divergent; 
stigmas fimbriate, persistent on the large wings of the fruiting calyx. Achene ovate, lenticular. 
Embryo straight, borne in the centre of the endosperm. [Greek, sour, from the acid leaves. ] 
Two known species, the following, and one in the 
Himalayas. 
1. Oxyria digyna (1,.) Camptdera. 
Mountain Sorrel. (Fig. 1315.) 
Rumex digynus I. Sp. Pl. 337-1753. 
O. digyna Camptdera, Rumex, 155. f/. 3. /. 3. 18109. 
Oxyria rentformis 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%/— 
114’ 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 ob- 
long, the inner erect, the outer reflexed in fruit; 
achene 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. Also in northern Europe and 
Asia. July-Sept. 
5. FAGOPYRUM Gaertn. Fr. & Sem. 2: 182. 1791. 
Annual or perennial rather fleshy usually glabrous leafy herbs, with erect, simple or 
branched, striate or grooved stems. Leaves alternate, petioled, hastate or deltoid, with ob- 
lique, cylindric or funnelform ocreae. Flowers small, white or green, in terminal or axillary 
usually paniculate racemes, perfect, borne solitary or several together from each ocreola, 
slender-pedicelled. Calyx about equally 5-parted, persistent and unchanged in fruit, the 
segments petaloid, shorter than the achene. Stamens 8, included; filaments filiform, gla- 
brous; anthers oblong. Ovary 1-celled, 1-ovuled; style 3-parted; stigmas capitate. Achene 3- 
angled. Embryo central, curved, dividing the mealy endosperm into two parts; cotyledons 
broad. [Greek, beech-wheat, from the similarity of the grain. ] 
About 6 species, natives of Europe and Asia. 
Racemes panicled or corymbose; angles of the achene not crested. 1. F. Fagopyrum. 
Racemes mostly simple; angles of the achene crested, undulate. 2. F. Tataricum. 
1. Fagopyrum Fagopyrum (L.) Karst. Buckwheat. (Fig. 1316.) 
ai, 
VAs 
Polygonum Fagopyrum U,. Sp. Pl. 364. 1753. 
Fagopyrum esculentum Moench, Meth. 290. 1794. 
FF. Fagopyrum Karst. Deutsch. Fl. 522. 1880-83. 
Annual, glabrous except at the nodes, stem 
strongly grooved when old, 1°-3° high. Leaves 
hastate, 1/-3’ long, abruptly narrowed above the 
middle, acuminate, the nerves on the lower sur- 
face slightly scurfy; ocreae brittle and fugacious; 
racemes mostly panicled, sometimes corymbose, 
many-flowered, erect or inclined to droop; pedi- 
cels as long as the calyx; segments white or whit- 
ish; stamens included; style-branches deflexed 
in fruit; achene acute, 214/’ long, about twice as 
long as the calyx, its faces pinnately-striate 
when mature, the angles acute, entire. 
In waste places, and persistent in fields after cul- 
tivation. Reported from almost all parts of the 
northern United States and southern British Amer- 
ica, Native of eastern Europe or western Asia. 
June-Sept. 
