Powell
Amaranth
(Amaranthus powellii, AMAPO)
U.S. Distribution:
Northern and western U.S.
Line
drawings of plant features
Descriptions
Seedlings: Seed
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.
Adults:
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.
Technical Characters
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.
Management
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. |