Polygonum hydropiper L.
water pepper
Almost glabrous annual herb; stems erect or suberect, to c. 75 cm tall, often reddish; roots rather slender. Lvs on main stem similar to those on branches, subsessile or shortly petiolate. Lamina 1-12 × 0.3-2 cm, lanceolate or linear-lanceolate, bright or deep green, with small translucent glandular dots; margins ciliolate and ± undulate; base cuneate to attenuate; apex obtuse to acuminate. Ochreae to 2 cm long, reddish brown, truncate, with 0-few fringing bristles, ± flared at upper nodes. Racemes slender, spike-like, to c. 7 cm long, at least partly curving downwards, the lower fls often distant; pedicels short, enclosed by bracts at anthesis, later protruding. Perianth 1.5-3 mm long, prominently dotted with brownish glands, usually pink or rose, rarely white, accrescent; segments ± broad-elliptic, strongly imbricate. Nut 2.5-3 mm long, trigonous or biconvex, dark brown or black, finely granular and appearing dull to moderately shining.
N.; S.: abundant in lowland areas throughout.
Temperate Eurasia, N. Africa 1906
Lakesides, ponds, ditches, drains, riverbeds and wet, poorly drained pastures and waste land.
FL Nov-Jun.
Possibly poisonous (Connor 1977).
P. hydropiper is distinguished from the related P. punctatum, especially in the South Id, by the very strong peppery taste of the lvs, their deeper green colour, the ± flared ochreae, as well as the rather dull, granular frs and the usually pink fls.
