SMOOTH PIGWEED, Amaranthus hybridus L. 1, upper stem with leaves and flower clusters; 2, flower; 3, seed. Annual, reproducing by seeds. Taproot shallow, reddish. Stems erect, up to 8 feet (2.4 m) tall, branching freely if not crowded. Leaves dull green, usually at least 6 inches (15 cm) long when mature, ovate to lanceolate. Flowers green, small, in slender, lax, paniclelike spikes with many short, crowded lateral branches. Bracts and sepals slightly longer than utricles. Sepals straight and acute. Seeds shiny black, lens-shaped, ovate, notched at narrow end, about 1 mm in diameter. Found in cultivated fields, yards, fence rows, and other waste places. Other species such as redroot pigweed and Powell amaranth (Amaranthus powellii S. Wats) are similar to smooth pigweed in morphology and weedy habits, and may often be found in the same area. Powell amaranth has longer floral bracts than smooth pigweed; has straight, acute sepals that are longer than the utricle; has a stiff terminal inflorescence that either is simple or has a few widely spaced, long lateral branches; and is found mainly in northern part of region.