Rumex tenuifolius (Wallr.) Á.Löve

Glabrous dioecious perennial, ± reddish, with a slender branched rhizomatous system; stems erect, to c. 25 cm long. Petioles long and slender on lower lvs, much shorter on upper lvs. Lamina linear, usually 10–40 × 1–2 mm (excluding lobes), entire except for narrow, spreading basal lobes to c. 1.5 cm long; margins inrolled except when young; apex acute. Upper lvs smaller and very narrowly linear. Infl. to c. 12 cm long, with slender branches, leafless except near base. Fls fascicled. Pedicels slender, glabrous. Perianth of ♂ fls 0.8–1.2 mm long. Outer perianth whorl of ♀ fls c. 0.5 mm long, not reflexing at fruiting; inner perianth whorl erect, enlarging at fruiting. Fr. valves c. 1.3 mm long, suborbicular, entire; tubercles 0. Nut c. 1.5 mm long, ± crimson, sharply angled.

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

Flowering: Nov.–Mar.