Rumex crispus L.  

An erect, little-branched perennial, between 35 and 120 cm tall.  Basal leaves oblong-lanceolate, rounded or narrowed at the base, with undulate, crisped margins, up to 30 cm long; petiole up to 10 cm long. The upper leaves smaller, narrower. Flowers green, in dense whorled clusters, forming lateral or terminal spike-like racemes. Perianth segments up to 2 mm long, oblong to lanceolate. Valves up to 6 mm long, broadly ovate, cordate, with unequal tubercles at their base.