Other common names.—Bitter dock, common dock, blunt-leaved dock, butter dock. (Fig. 6.)
Fig. 6.—Broad-leaved dock (Rumex obtusifolius L.). First year’s growth.
Range and habitat.—The range of this very common weed extends from the New England States to Oregon and south to Florida and Texas; it occurs in waste places.
Description.— Broad-leaved dock differs from the yellow dock principally in its more robust habit of growth. It grows to about the same height, but its stem is stouter, and the leaves, which are wavy along the margin as in the yellow dock, are much broader and longer. The lower leaves have long stalks, and are from 6 to 14 inches in length, with heart-shaped or roundish bases, while the upper ones are from 2 to 6 inches long and are on short stalks.
Fig. 7.—Leaf, fruiting spike, and root of broad-leaved dock.
The green flowers appear from June to August, and are in rather long, open clusters, the groups rather loose and far apart. In all of the docks here mentioned, the three inner divisions of the calyx (outer covering of flower) in fruiting form a kind of triangular nut, like the grain of buckwheat (to which family, Polygonaceæ, the docks belong), and one or more of these divisions bear on the back a small granule. The difference between flower and fruit is barely distinguishable when seen from a little distance so long as the fruit is immature, both being green, but later in the season, as the fruit ripens, the spikes take on a rusty-brown color. (Fig. 7.)