THE PERSIC ARIA FAMILY 
125 
floats in the water and throws up the flower-clusters above the surface of the water on short stalks, 
the stems float, root at the lower joints, and the leaves are broad, egg- or lance-shaped or oblong, 
smooth or leathery, on long stalks ; when the plant is found growing in dried-up pools or ditches, 
the stem is creeping and rooting at the base and then erect, about 1 foot high, and the leaves are 
nearly stalkless, lance-shaped, and slightly hairy. 
Very common. In pools and ditches, or on mud or marshy ground; throughout England, 
Scotland, and Ireland. July — September. Perennial. 
13. Bistort, Snakeweed. (Polyg onum Bistorta. Linn.)— A very distinctive species 
with a solitary, erect, oblong, handsome spike, 1-2 inches long, of pale rose- or flesh-colour flowers ; 
the 5-cleft perianth without glands, the stamens 8 in number and protruding (exserted), the styles 
3, and the nut 3-sided. [As described in the genus Persicaria (Polygonum).] The stem is 1-2 
feet high, erect, unbranched, and with a few almost stalkless, small egg-shaped (ovate) leaves and 
numerous large egg-shaped root-leaves with long winged stalks. The root is thick and creeping. 
\Plate 41. 
Not common. In moist meadows, by the side of streams ; in England and the south of Scotland, 
rare in Ireland. June — September. Annual. 
14. Viviparous Bistort. (Polyg onum vivip'arum. Linn.) — Flowers white or flesh- 
colour, sometimes very few, in a solitary, erect, slender, loose cluster, with flowers at the top and 
small red bulbils instead of flowers below ; the perianth 5-cleft, without glands, the styles 3, and 
the nut 3-sided. [As described in the genus Persicaria (Polygonum).] The stem is 6-18 inches 
high, erect, and simple ; the leaves are narrowly lance-shaped with the margins rolled back 
(revolute), those of the root on long, wingless stalks, and those of the stem on shorter stalks ; the 
stipules are close to the stem and not fringed ; and the root is creeping. 
Rare. In mountain pastures, by the side of mountain streams ; in Wales, the north of England, 
and the Scotch Highlands as far as the Shetland and Hebrides Islands, very rare in Ireland. 
June — July. Perennial. 
II. ^BUCKWHEAT. (FAGOPYRUM. Hill.) — A genus not native in the British Isles, though 
one species is occasionally found, and differing from Persicaria (Polygonum) chiefly in the 
internal structure of the seed (a point with which this book does not deal), the embryo being 
in the centre of the seed and the cotyledons being large, leaf-like and plaited, whereas in the 
Persicaria (Polygonum) the embryo is at one side of the seed and the cotyledons are flat. 
*Common Buckwheat. (Fagopyrum sagittatum. Gilib.) — The flowers are 
pinkish or cream, in leafless branched clusters (cymose panicles) ; the perianth 5-lobed, the 
stamens 8, the styles 3 terminating in clubbed stigmas, the nuts 3-sided, longer than the 
perianth. The stem is about 1 foot high, branched ; the leaves are heart-shaped (cordate) with 
pointed lobes, the lower stalked and the upper stalkless and clasping the stem (amplexicaul) ; and 
the stigmas not fringed. (. Fagopyrum esculentum. Moench .) 
This plant is cultivated in the British Isles for food for game. 
Not native. In cultivated ground and waste places ; frequent in places where it is cultivated but 
not remaining; in England, Scotland, and Ireland. July — August. Annual. 
III. MOUNTAIN SORREL. (OXYR'IA. Hill.) — A genus containing the one species : — 
Common Mountain Sorrel. (Oxyr'ia digyna. Hill.) — Flowers green, 2-6 in clusters 
(whorls) round the stem forming a long simple or branched cluster (panicle) terminating the 
stem. Perianth of 4 lobes, in 2 rows, the 2 inner ones becoming larger in fruit, inserted below 
