University of Missouri Extension

IPM1007, Revised November 2009

Practical Weed Science for the Field Scout: Corn and Soybean

Pigweed, smooth (Amaranthus hybridus)

Summer annual broadleaf

Smooth pigweed
Smooth pigweed

An erect summer annual that may reach as much as 6-1/2 feet in height. Cotyledons are narrow and have a reddish tint. First true leaves are alternate, ovate in shape, and slightly notched at the tip of the leaf blade. Hairs may occur on the leaf margins and along veins, especially along the lower leaf surfaces. Stems also have short hairs, more so than with redroot pigweed. Mature plants have leaves that are alternate, ovate in outline, and generally with less wavy margins than redroot pigweed. Flowers are inconspicuous and produced in dense, compact terminal and axillary panicles that are longer than those of redroot pigweed and not prickly to the touch.

Smooth pigweed
 

 

Wild thing
 

IPM1007 Practical Weed Science for the Field Scout: Corn and Soybean | University of Missouri Extension

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