(Amaranthus powellii, AMAPO)
Northern and western U.S.
drawings of plant features
leaves are very long and narrow. First true leaves are egg-shaped.
Seedlings may be deep red or green in color. As seedlings mature they
become lightly hairy.
Powell amaranths are tall plants with few branches. Stems and leaves tend
to be red or green and lightly hairy. Leaves are egg-shaped. Seedhead
branches are few and are usually very long, thick, and prickly.
Bracts long, 5-7mm. Tepals 3-5, this number often varying
between flowers on a single individual, the first one or two tepals (those
located immediately behind the bract) are longer than the fruit; the
remaining tepals often shorter than the fruit; apices acute to acuminate,
straight. Stigmas 3.
Powell amaranth appears to be restricted to the northern
two tiers of Iowa counties, especially in the northeast. It is a major
weed in Minnesota, Wisconsin, and northern Illinois. Powell amaranth
should respond to the same control strategies that are effective against
redroot pigweed. Triazine resistant biotypes have been reported.