This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The habitat of this species is watery places. The habit is more or less erect, from a prostrate base. The stem is creeping, rooting below, much branched. The leaves are shortly-stalked, lance-shaped, elliptic, wavy, more or less acute, glandular below, fringed with hairs, with smooth ocreae, which are short, swollen, fringed with hairs, or not. The flowers are greenish-pink, in curved, loose racemes, which are interrupted, slender and drooping above, rarely erect. The green and rose perianth has a few large glands. There are 6-8 stamens, 2 functionless. The 2-3 styles are nearly distinct or free. The fruit is large, flattened, plano-convex, or 3-angled, as long as the perianth, opaque, black, dotted, rough, ovate-acute. The plant is 1-3 ft. high, flowering in August and September, and is a herbaceous annual.
The habitat of this species is wet places. The habit is more or less erect, prostrate below. The stem roots at the base, and is branched and slender. The leaves are shortly-stalked, lance-shaped, wavy, elliptic, more or less acute, fringed with hairs, glandless, with loose, funnel - shaped ocreae or stipules, strongly fringed with hairs. The flowers are greenish-pink, in slender, more or less erect, long, loose, solitary, interrupted spikes or racemes, thickened upwards, leafy below, with sepals or perianth white, with faint nerves, without glands. There are 5-6 stamens. The 2-3 styles are connected half-way up. The nuts are large, rough, shining, black, narrow, ovate-acute, plano-convex, or 3-angled, as long as the perianth. The plant is 1-2 ft. in height, flowering in August and September, and is a herbaceous annual.
This is a weed of cultivation and waste ground, damp places, native in marshes and on river-banks. The habit is erect or ascending. The stems are branched, with swollen nodes. The leaves are flat, ovate, lance-shaped, spotted, more or less stalkless, acute, fringed with hairs, downy, dotted below, without glands. The stipules are loose, strongly fringed with hairs. The flowers are in dense racemes, or spikes, compact, ovate to oblong-, cylindrical, terminal and axillary, the lateral stalkless. The perianth-segments are red or white, smooth (like the stalk), without glands as a rule. There are 5-8 stamens, 2-3 styles, united half-way. The outer anthers open inwards, the inner outwards. The fruit is plano-convex, or 3-angled, flattened, gibbous one side, hardly covered by the perianth-segments. The plant is 1-2 ft. high, flowering from July to October, and is a herbaceous annual.
The habitat of this plant is damp ground, mountain valleys, waste places, wet meadows and ditches, or spots liable to be flooded. The habit is erect, the stem very stout. The leaves are very large, the lower oblong, lance-shaped, heart-shaped, wavy. The flowers are in crowded, leafless whorls. The sepals bear no tubercles, are heart-shaped, enlarged, entire, membranous. The nut is elliptical. The plant is 1-3 ft. in height, flowering in July and August, and is a herbaceous perennial.