P. cuspidàtum, Sieb. & Zucc. Perennial, erect, stout and tall, glabrous except the loose axillary panicled racemes; leaves round-ovate, shortly acuminate, truncate or cordate at base; outer sepals broadly winged in fruit.—Occasionally escaped from gardens. (Japan.)
5. FAGOPỲRUM, Tourn. Buckwheat.
Calyx petal-like, equally 5-parted, withering and nearly unchanged in fruit. Stamens 8. Styles 3; stigmas capitate. Achene 3-sided, longer than the calyx. Embryo large, in the centre of the albumen, which it divides into 2 parts, with very broad and foliaceous plaited and twisted cotyledons.—Glabrous annuals, with triangular-heart-shaped or halberd-shaped leaves, semicylindrical sheaths, and corymbose racemes or panicles of white flowers, often tinged with green or rose-color. (Name from fagus, the beech, and πυρός, wheat, from the resemblance of the grain to the beech-nut; so the English name Buckwheat, from the German buche, beech.)
F. esculéntum, Moench. (Buckwheat.) Smoothish; flower with 8 honey-bearing yellow-glands interposed between the stamens; achene acute and entire, smooth and shining.—Old fields, remaining as a weed after cultivation, and escaping into copses. June–Sept. (Adv. from Eu.)
F. tatáricum, Gaertn. (India-wheat.) Flowers very small, on shorter pedicels; achene very dull and roughish, the sides sulcate.—An occasional escape from cultivation. (Adv. from Asia.)
6. POLYGONÉLLA, Michx.
Flowers perfect or polygamous-diœcious. Calyx 5-parted, petaloid, loosely persistent about the achene, the 3 inner divisions often enlarging in fruit, in which case the outer are usually spreading. Stamens 8. Styles 3, and achene 3-angular. Embryo slender, straight or nearly so, toward one side of the albumen.—Slender glabrous annuals or perennials, with alternate mostly linear leaves jointed at the base, and rather rigid truncate or oblique naked sheaths and bracts. Flowers on solitary jointed pedicels (nodding in fruit) in slender panicled racemes. (Diminutive of Polygonum.)
1. P. articulàta, Meisn. Annual, erect, branching, glaucous, 4–12´ high; leaves linear-filiform, deciduous; flowers rose-color, nodding, in very slender racemes, the calyx a little enlarged in fruit; 3 inner filaments dilated at base; achene exserted, smooth. (Polygonum articulatum, Gray.)—Dry, sandy soil; on the coast from Maine to N. J., and along the Great Lakes.
7. BRUNNÍCHIA, Banks.
Calyx 5-parted; the divisions somewhat petal-like, oblong, connivent and coriaceous in fruit, the base and almost the whole length of the pedicel winged on one side. Stamens 8; filaments capillary. Styles 3, slender; stigmas depressed-capitate. Ovule pendulous on a slender erect funiculus; seed erect, 6-grooved. Achene obtusely triangular, partly 3-celled, enclosed in the indurated calyx. Embryo in one of the angles of the mealy albumen, somewhat curved.—Somewhat shrubby with grooved stems, climbing by tendrils from the ends of the branches. (Named for F. Brunnich, a Danish naturalist.)