Photo Courtesy of Steve Dewey, Utah State University, bugwood.org
Growth Characteristics: A perennial species, curly dock grows 1 ½ to 4 feet high, and reproduces by seed. It generally flowers from June to October. Flowering is delayed by shoot removal. A large, mature curly dock can produce up to 40,000 seeds per year. The seeds are shed continuously from late summer through the winter. Seeds are capable of surviving in undisturbed soil for 50+ years and seed numbers in soil have been estimated at 5 million per acre. Young seedlings vary in color from entirely green to being red tinged in cooler months.
Flowers: Small flowers occur on the upper portion of the stem, and are yellowish green at first, but become rosy then reddish brown. The 6 flower parts do not look like petals. The 3 inner parts become greatly enlarge and heartshaped. They surround the tiny fruit, and have the appearance of wings. At maturity, these wings are 1/8 to ¼ inch long, and usually have a little wart-like thickening on the back. The flowers have 6 sepals.
Fruits/Seeds: Seeds are borne in a large, loose, branching cluster, 1 ½ - 2 feet long at the top of the stems. Each flower produces one glossy, triangular achene, about 1/12 inches long. A papery 3-valved or 3-winged structure surrounds the achene.
Leaves: Bluish-green, lanceshaped leaves. Alternate above, often a large basal rosette is produced late in the fall. Leaves are 3-12 inches long (or more including the stock), with noticeably wavy and curly edges. Leaves decrease in size towards the top of the plant. There is a membranous sheath at the leaf base. Leaves become more reddish-purple with age.
Stems: Smooth, fleshy stems die back each fall, and new ones arise each spring. Stems have swollen nodes and are often reddish in color.
Curly dock is common along roadsides and waste places. It is also an aggressive weed in permanent pastures, irrigation ditches, and in many cultivated crops. Leaves are poisonous to cattle and sheep. It is frequently associated with overwatering or standing water in low areas. Curly dock seedlings have a low competitive ability and find it difficult to become established in closed vegetation.
Soils: Curly dock prefers deep, moist soil.
Seeds and vegetation of Curly dock are toxic to poultry and can cause dermatitis and gastric problems in cattle. It is an alternate host to many crop diseases.
Curly dock is used extensively in the treatment of chronic skin complaints such as psoriasis. The anthraquinones present have a markedly cathartic action on the bowel, but in this herb they act in a mild way. Thus, it is useful for constipation, working as it does in a much wider way than simply stimulating gut muscles. It promotes the flow of bile and has that somewhat obscure action of being a blood cleanser. The action on the gall-bladder gives it a role in the treatment of jaundice when this is due to congestion.