Plants perennial, glabrous or very indistinctly papillose on veins of leaf blades abaxially, with vertical rootstock. Stems erect or as-cending, divaricately branched in distal 2- 3, 30-80(-100) cm. Leaves: ocrea deciduous or partially persistent; blade shape variable, oblong to lanceolate or lanceolate-linear, often panduriform, contracted near or proximal middle, (3-)5-15(-17) × 1-3(-5) cm, base truncate, slightly cordate, or broadly cuneate, margins entire, normally slightly undulate and crisped, apex acute or subobtuse. Inflorescences terminal, occupying distal 2/ 3 or most of stem, lax, interrupted in proximal part or throughout, broadly paniculate, branches spreading. Pedicels articulated in proximal 1/ 3, filiform (occasionally thickened distally), 2.5-5 mm, usually as long as or slightly longer than inner tepals, articulation distinctly swollen. Flowers 5-8(-10) in rather lax remote whorls; inner tepals broadly to narrowly triangular, 2.5-4 × 1.5-2.3 mm (excluding teeth), base truncate or broadly cuneate, margins prominently dentate, apex acute and ending in hooked tooth, teeth 3-5, at each side of margins, hooked, 0.5-1.5 mm; tubercles absent, or midveins indistinctly swollen. Achenes reddish brown, 1.8-2.3 × 1.2-1.5 mm. 2n = 20.

Flowering summer. Waste places, near wool-combing mills; 0 m; introduced; S.C.; Europe; Australia; Pacific Islands (Java, New Guinea, New Zealand, Timor).

Rumex brownii, an uncommon 'wool alien' in North America, was collected in South Carolina in the late 1950s (J. E. Dawson 1979). It is uncertain if it persists there. It occasionally occurs in Europe as a casual alien. This species is a member of subsect. Acrancistron Rechinger f. (see K. H. Rechinger 1984), which includes two Australian species.