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: June to September.
Seed-time: August to November.
Range: Maine to British Columbia, southward to Florida and
Mexico. Habitat: Cultivated grounds; waste places.
Stem ten to twenty inches high, leafy to the top, slender, often decumbent, sometimes erect, usually loosely branched. Leaves rhombic-ovate, thin, green on both sides, with large, coarse, wavy but sharply pointed teeth, bases broadly wedge-shaped, truncate, or slightly rounded, with petioles shorter than the blades. Panicles in small, branching, divergent, somewhat corymbose clusters, axillary, and shorter than the leaves; calyx-lobes not wholly enclosing the seed, which is sharp-edged and very flat.
Means of control the same as for Smooth Pigweed.