Time of bloom: May to September.
Seed-time: June to November.
Range: All parts of North America except the extreme North.
Fig. 55. - Tall Sorrel (Rumex Acetosa). X 1/6.
Rootstocks extensively creeping, branched, yellowish, tough and fibrous, with tufts of feeding rootlets at intervals of a few inches. Stems three inches to a foot or a little more in height, slender, erect or nearly so, usually simple. Leaves halberd-shaped, long-petioled, the basal auricles spreading; stem leaves often without auricles; they are smooth, light green, papillose, filled with an acid juice - which is rather pleasant to taste but very unwholesome, as it is an acid oxalate, which, veterinarians say, is poisonous to horses and sheep. Flowers dioecious, in erect, interrupted, panicled racemes, the staminate ones conspicuously yellow because of the out-thrust, pollen-loaded anthers, the fertile ones with reddish calyx-lobes and feathery, crimson stigmas. Achene three-angled, brown, exceeding the calyx-lobes. Sorrel seed is a frequent impurity of commercial seeds, particularly of alsike clover, from which it is especially difficult to separate. (Fig. 56.)
Cultivate and enrich the ground, correcting its acid condition with heavy applications of lime. Grain crops infested with Sorrel are so robbed of moisture as to yield very poor returns; they may be helped by a spray of Iron sulfate applied just as the weed comes into bloom; the rootstocks take no harm, but much of the leaf surface is destroyed and seed development prevented for that season. Give surface cultivation, after harvest, exposing the fibrous root-stocks and destroying the leaf-growth, and also stirring dormant seeds into life. Reseed heavily, smothering the weed with strong grasses or clover.
Fig. 56. -Field Sorrel (Rumex Acetosella). X 1/4.