Native to Europe, but now spread throughout North America.
A winter annual broadleaf. Found in turf and landscapes, orchards or nurseries, and in many crop settings. In favorable environments it may act as a biennial or even a short-lived perennial.
Reproduction is from seed, with seedlings emerging in both fall and very early spring, when soil temperatures are cool and moisture is available.
Mature plants generally grow no taller than about 1 foot. Stems begin growth lying close to the ground, but then curve and grow upright. The sections of the stem touching the ground may root at the nodes. Stems are somewhat square, green to purple, and hairless.
Leaves are less than 1 inch long and are broadly oval with scalloped edges. They are opposite on the stems, and the lower leaves may have very long stalks
Flowers are pink, reddish, or purple, and grow in whorls from the axils of the upper leaves. They are tube shaped, and are up to 2/3 of an inch long and extending well beyond the leaves they arise from.
Characteristicts Important to Control:
A winter annual that requires cool, moist soils. Germination of seeds may be fall or early spring, and seedlings may over-winter.