This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Perennial. Propagates by seeds and by rootstocks.
Fig. 54. - Broad-leaved Dock (Rumex obtusifolius). X 1/8.
Time of bloom: May to July.
Seed-time: June to August.
Range: Eastern Canada to Vermont, New York, and Pennsylvania; locally south and west. Habitat: Gardens, fields, roadsides, and waste places.
Usually an escape from gardens where it has been cultivated for "greens," though there are much better pot herbs which are not so unruly. Stems eighteen inches to three feet tall, erect, simple, smooth, slightly grooved. Leaves two to five inches long, arrow-shaped, the auricles at base not spreading; basal leaves on long and slender petioles, those on the stems nearly sessile. Flowers dioecious, the racemes erect, and crowded, or interrupted. Calyx green, the valves winged in fruit, rounded at apex, heart-shaped at base. Achenes dark reddish brown, pointed, three-angled, smooth and shining. (Fig. 55.)
Frequent and close cutting throughout the growing season will prevent seed development and starve the rootstocks. Small areas should be grubbed out and destroyed.