This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Annual. Propagates by seeds.
Time of bloom: Throughout the year.
Seed-time: Throughout the four seasons.
Range: Throughout the world.
Habitat: Gardens, cultivated fields, lawns, meadows, waste places.
In spite of its frail appearance, this plant is probably the hardiest and the most persistent weed on earth. Its range nears the Arctic Circle, and the writer picked green and thrifty stems, bearing buds, flowers, and seeds, within a yard of a melting snowbank, during a "January thaw" of the present winter. The seed, though small, retains its vitality for many years.
Stems tufted, slender, weak, many-branched, creeping or ascending, with a fringe of hairs down one side. Leaves usually not much more than a half-inch in length, ovate, smooth, entire, the lower ones with hairy petioles, the upper ones sessile, so numerous that the plant often covers the ground like a green mat. Flowers in terminal, leafy cymes or solitary in the axils, on very slender pedicels; each of the five small, snowy petals is cleft down its center, forming a white star, which is set within a larger green one, formed of five oblong, pointed hairy sepals, joined at their bases. Stamens three to seven and styles three or four. Capsule ovoid, longer than the calyx and opening at the apex by six or eight teeth, or twice as many as the styles. Seeds very numerous, round, brown, flattened, roughened with rows of small tubercles. (Fig. 91.)
Fig. 91.- Common Chickweed (Stellaria media). X 1/2.
In gardens, constant hoeing or hand-weeding, while the plants are young, is necessary in order to suppress this weed; but among crops that will not be injured by the treatment, such as peas, strawberries, and grain, a spray of Iron sulfate will kill young Chickweed.