Rumex obtusifolius L.
broad-leaved dock
Stout, tap-rooted ⚥ or monoecious perennial; stems usually 30-100 cm tall, erect. Petiole of lower lvs usually much < lamina and with long, white, membranous ochreae. Lamina of lower lvs to 35-(50) × 15-(20) cm, ± oblong or oblong-ovate, ± membranous, often puberulent below, especially on veins; margins ± undulate; base cordate to rounded; apex obtuse or subacute. Cauline lvs becoming progressively smaller, narrower, and more tapered at base and apex. Infl. usually with several spreading branches; Whorls 10-many-flowered, usually contiguous, sometimes some rather remote; pedicels ± recurved, slender, glabrous, the lower subtended by a small lf; fls dense, strongly protandrous. Perianth 1.5-3 mm long, generally green at first, often becoming red where exposed to strong light; segments with hyaline margins; outer segments ± oblong or elliptic-oblong, not reflexed at fruiting; inner segments erect, greatly enlarged at fruiting. Fruiting valves 3.5-5 mm long, ± triangular with truncate base; margins with some teeth 1-1.7 mm long, but usually several shorter; apex rounded to obtuse; tubercle prominent, rosy, ± oblong, 2-2.5 mm long. Nut c. 2.5 mm long, glossy brown, sharply angled.
N.; S.; St.: abundant throughout; K., Ch., C.
Europe 1864
Usually near habitations, also common to abundant elsewhere in pastures, river banks and open moist places, and a major weed of gardens and arable land.
FL Jul-Apr-(Jun).
Plants are often very large and prolific around stockyards, cowsheds and other places with very high nitrogen levels. R. obtusifolius is often simply called dock and in very modified habitats is generally the commonest sp. of the genus.
