have crowded, highly branching spikes, different from the long, nodding, thin, lightly branching terminal spikes of Palmer amaranth. Mature Palmer amaranth has thinner stems than redroot pigweed, and its combination of non-wavy, egg shaped, round-tipped leaves with very long leaf stalks and white veined undersides sets the mature plant apart. Similar species: Palmer amaranth seedlings are similar to redroot pigweed ( Amaranthus retroflexus L.), smooth pigweed ( Amaranthus hybridus L.), Powell amaranth ( Amaranthus powellii S. Fruits are brown, triangular or pyramid shaped sacs, with 3-5 spines at their tip sacs rupture at maturity, releasing one glossy, round, dark red-brown to black, 0.04-0.06” (0.1-0.15 cm) long seed. Female spikes are similar, with thick, stiff, notched bracts with a small spine located in the notch. Terminal spikes of male plants are yellow and 0.5-1.5 ft (15-45 cm), with thin, triangular, green bracts around individual flowers. The longest spike is located on the main stem smaller spikes are present at branch tips and in upper leaf-stem joints. Plants are either male or female, with individual, inconspicuous, green flowers grouped in spikes spikes are soft or lightly spiny, thin, 0.3-0.8” (0.8-2 cm) wide, often nodding, and largely unbranched. The relatively shallow taproot is reddish near the soil surface. Leaves are alternate, hairless egg to lance shaped, 2-8” (5-20 cm) long by 0.5-2.5” (1.3-6 cm) wide, with conspicuous white veins on the undersides, and long leaf stalks. Upper stems and branches are greener, less hairy, and have narrower, pointier leaves than those located lower on the plant. The coarse, red stem of mature plants will reach 1.5-6.5 ft (0.5-2 m) tall with long, thin branches spaced far apart on the stem. ![]() Young leaves are alternate, egg shaped, and roughly 5 times longer (0.4-0.5” = 1-1.3 cm) than wide, with notched tips. Cotyledons are lance shaped, hairy, and red to green in color. Other common names: carelessweed, Palmer pigweedĭescription: Seedling stems are usually red, sometimes green, and sometimes slightly hairy. See Pigweed Identification for more information on how to identify Palmer amaranth.
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