Curly dock (Rumex crispus
) is a nitrate-accumulating, perennial broadleaf weed. It has narrow, dark green, hairless leaves with curly or wavy margins or wider leaves with smooth to finely ruffled margins. R. crispus
is found virtually everywhere in the world, naturalized and in some places invasive.
Curly dock has a large, fleshy, yellow-orange colored taproot that extends deep into the soil, enabling them to survive drought periods and outcompete other vegetation. Small, greenish flowers in whorled clusters at the end of the upright stems appear early summer. It turns a rusty-brown color at maturity.
Curly dock contains toxic anthraquinones, oxalates and tannins.