Rumex obtusifolius L.

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.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

Flowering: Jul.–Apr.–(Jun.)