A perennial, robust, erect herb up to 1 m. tall that always grows near water. The roots are creeping in black, muddy soil.

The inside tissues are yellow-brown. All the leaves arise from a central tuft near the top of the apex, just above the soil level. They are large, dark bluish green, kidney-shaped and covered with hairs on both surfaces. The margin of the leaves is irregularly toothed. The veins are very noticeable on the lower surface of the leaf, radiating from the point where the petiole joins the leaf, referred to as palmate radiation.

The flowers are numerous, small and not very noticeable, tiny pinkish reddish brown, borne on a long slender spike, which is taller than the leaves. On each spike there will be female flowers at the base, male flowers at the top and bisexual flowers in the middle.