Ohio Perennial and Biennial Weed Guide

Family:

Smartweed (Polygonaceae) family

Other Names:

Rumex elongatus, curled dock, sorrel, sour dock, yellow dock, narrow-leaved dock.

Origin and Distribution:

Curly dock is a native of Europe, but today it occurs worldwide: above the Arctic Circle and on all continents. It is considered a weed in about 40 countries, making it one of the world's most successful noncultivated colonizing plants. Curly dock is a common but not necessarily serious weed in 16 crops including pastures, hay crops, small grains, orchards, lawns, and home gardens. It occurs throughout Ohio and surrounding states, and is commonly found along roadsides and waste areas where it tolerates poor drainage but favors nutrient rich soils.

Plant Description:

Curly dock is a herbaceous perennial with tall, erect stems. It reproduces by seeds and a thick fleshy taproot. It is a variable species that hybridizes with other dock species.

• Root System:

  A stout, somewhat branched, yellow taproot may extend as deep as 4 feet, with side branches up to 3 feet long.

• Stems:

  Stems are erect and tall (1 to 4 feet), arising solitary or in small groups from the root crown. Stems are smooth and sometimes ridged. A papery sheath surrounds the stem at each node. Stems turn red-brown at maturity and often persist into winter.

• Leaves:

  Leaves of curly dock are long and relatively narrow, with curly or wavy margins resembling crisped bacon. Curly dock leaves sometimes have a bluish green color. Cotyledons are very narrow, grey-green, with a mealy surface, and first true leaves are mostly round. The base of rosette leaves is rounded to heart-shaped. Stem leaves are alternate (one per node), with a short petiole. Leaves decrease in size up the stem, the petioles flatten at the base and wrap around the stem.

• Flowers:

  Flowers are not showy, but are small green three-winged sepals that become brown at maturity. They appear at the end of long, slender stalks (pedicles), attached in whorls (several per node) along the upper part of the elongating and branched stem. The flowers lack nectar and pollen is spread by wind.

• Fruits and Seeds:

  Fruits of curly dock consist of three heart-shaped bracts or wings (sepals or valves) with smooth (not toothed) edges. One of the wings encloses a single, triangular, sharp-edged, glossy red-brown seed.

Similar Species:

Broadleaf dock (Rumex obtusifolia), which has wide leaves with more-or-less smooth margins, is less widely distributed world-wide and in the United States than curly dock. In broadleaf dock, the sepals, and hence wings of the fruit, are irregularly toothed.

Biology:

Curly dock is a cross-pollinated species that exhibits great variation in morphology and physiological characteristics. Seeds are released from dormancy at various times of the year, and germinate in response to light and fluctuating temperature. Seedlings that emerge early in the growing season produce flowers and seeds in the first year. Seedlings that emerge in autumn form an overwintering rosette and flower the following year. After about 40 days of growth, a seedling can produce shoots from the root crown. In springtime, shoots regenerate from buds at the upper 2 inches of the taproot. Flowers appear in May, about 9 weeks after shoot emergence, and can continue into October and November. Some plants flower twice a year. A single plant can produce 60,000 seeds, some of which germinate readily, while others can remain viable in the soil for over 80 years. Some plants flower and die in one seasons whereas others live 3 to 5 years. Curly dock establishes from seeds only at open, disturbed sites; it does not tolerate competition or tillage.

Toxicity:

Ingestion of foliage or seeds has been responsible for several gastric disturbances and dermatitis in cattle and serious toxicity in poultry. Leaves contain soluble oxalates that can be toxic if consumed in large quantities or if not cooked properly.

Facts and Folklore:

• Dried fruit stalks have been used in flower arrangements and holiday wreaths. Native Americans reportedly used the seeds in flour and meal; they cooked a mush from the seeds, but only in times of need.

• During early spring and summer the leaves are edible as cooked greens in limited quantities. Leaves reportedly are high in vitamins C and A.

• Various parts of curly dock were used medicinally for a variety of ailments including rheumatism, jaundice, scurvy, and skin diseases, and were administered as a syrup or in externally applied ointments.