Flora of the Hawaiian Islands
Literature for Rumex obtusifolius
Wagner et al., 1990, 1999. Literature for Rumex obtusifolius subsp. obtusifolius
Wagner et al., 1990, 1999.
   Polygonaceae -- The Buckwheat Family Bibliography
      Rumex obtusifolius
General Information
DistributionNative to Europe, now widely naturalized.
Erect perennial herbs; stems 6-12 dm long, striate, glabrous.
Leaves oblong-ovate to oblong-lanceolate, basal ones usually 25-45 cm long, 9-11 cm wide, cauline leaves 6-30 cm long, 2-11 cm wide, upper surface usually glabrous, lower surface usually papillose-pilose along veins, occasionally glabrous, margins subentire to erose, undulate, apex acuminate to obtuse, base truncate to subcordate, petioles usually 2-9 cm long, those of basal leaves up to 25 cm long.
Flowers unisexual (and the plants monoecious), usually 14-24 in clusters, these arranged in racemose, sometimes branched inflorescences; staminate flowers with outer tepals 0.8-1 mm long, the valves membranous, 1-1.3 mm long; pistillate flowers with outer tepals 1-1.2 mm long, the valves membranous, 1.5-2 mm long, enlarging to 4-5 mm long and becoming narrowly cordate in fruit, margins with straight or slightly curved teeth, some of which are 1-1.2 mm long, at least 1 of the valves with a tubercle, the tubercles unequal, 0.6-2 mm long.
Nuts dark brown, 2-2.4 mm long, the surface glossy.
2n = 20, 40, 60