Palmer amaranth
Family
AmaranthaceaeScientific Name
Amaranthus palmeri
Other Common Names:
carelessweed
Habit
This erect summer annual can be found flowering from June through October. Germination occurs from April through September.
Leaves
The alternately arranged leaves are lance to egg shaped and occur on long petioles. The leaves can be from 2 to 8 inches in length and 1/2 to 2 1/2 inches in length. The undersides of the leaves have prominent white veins. There is one central stem from which many side branches will arise. The central stem can reach 6 1/2 feet in height.
Identifying Characteristics
This plant can be distinguished from other pigweeds by its long narrow terminal spike. Another identifying feature is the lack of hair on the leaves.
Flower Seed Head
The small green flowers occur on a terminal spike up to 1 1/2 feet in length. Smaller spikes of flowers can be found on the stem above some leaf petioles. The male and female flowers are found on different plants.
Seed Fruit
The seeds develop in a utricle that can grow up to 2 mm in length. Each utricle contains one glossy black seed.
Where Found
This plant can be found infesting croplands.
Growth Habit
upright and nonwoody
Thorns or Spines
present
Approximate Flower Diameter
pencil
Dominant Flower Color
green
Flower Symmetry
not symmetrical
Leaf Hairs
no hairs
Leaf Shape
oval
Leaf Arrangement
alternate
Leaf Margin
entire
Leaf Structure
simple
Leaf Stalk
longer than leaf
Stem Hairs
no hairs
Stem Cross Section
round or oval
Milky Sap
not present
Root Structure
taproot
Life Cycle
summer annual
Ochrea
not present
Plant Type
Herb