Propagates by seeds. Time of bloom: March to October. Seed-time: May to November. Range: Eastern United States and Canada, from Quebec and Ontario to Florida.
Locally as far inland as Ohio. Habitat: Gardens, lawns, fields, meadows, and roadsides.
An inconspicuous but persistent little weed, as its season of bloom and fruit is both early and late and the seeds when undisturbed in the soil retain their vitality for several years.
Roots tough and fibrous, sending up a number of slender, light green, fork-branched stems, three to six inches long, usually rough-hairy but sometimes smooth, some erect and some prostrate and spreading on all sides.
Fig. 86. - Knawel Scleranthus annuus). X 1/2.
Leaves awl-shaped, opposite, with joined bases, and about a half-inch long. In their axils and at the ends of the stems are clustered the numerous minute greenish flowers; these have no petals, but have five or ten stamens, two distinct styles and a deeply cut five-lobed calyx (occasionally four-lobed) with a hardened, cup-like tube which later encloses and persistently holds the solitary seed. These hard seed-coverings - with their points broken off - are sometimes an impurity of grass and clover seeds. (Fig. 86.)
Autumn plants should be destroyed by surface cultivation in early spring. Where such tillage is practicable, persistent hoe-cutting during the growing season will suppress the weed. In lawns a few drops of carbolic acid, squirted on the crowns with a machine oil-can, destroys the plants with less defacement of the sward than the hoe would make.