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Amaranthus blitoides - mat amaranth

Scientific Family
Amaranthaceae
Synonyms
Amaranthus graecizans
Other common names
prostrate pigweed
Plant type
Forbs and Subshrubs
Origin
Introduced
Lifecycle
Annual
Height
Prostrate, 2 foot spread
Riparian
Yes

Herbaceous weedy annual with stems up to 2 feet long, branched from the base and mostly prostrate.

Female flowers of 4 to 5 tepals and intermixed with male flower of 3 to 4 tepals; inflorescences in axillary clusters, sometimes in terminal leafy spikes; leaf blades usually obovate to elliptic-spatulate; fruits open horizontally.

Habitat

In the arid west, usually occur in wetlands, but may occur in non-wetlands. Grows in disturbed areas, even in cracks of sidewalks.

Plant Community
Disturbed Areas
Riparian
Low elevation
0
High elevation
7200

Flower Characteristics

Short clusters of light green flowers develop from the axils of the leaves sometimes appear as terminal spikes.

Flower color
Light green
Flower shape
Inconspicuous
Tubular
No
First bloom month
June
Last bloom month
September
Flower clusters
Rounded

Leaf and Stem Characteristics

Leaves are up to 1 inch long and taper to a slender petiole. Stems vary in color from whitish-green to pale red. Mostly without hairs.

Leaf type
Simple
Leaf color
Dark green
Leaf shape
Round or oval
Leaf margin
Smooth
Leaf attachment
Alternate
Leaves clasp
No
Leaf hairs
None
Spines
No

Fruit and Seed Characteristics

The fruit is a bladder-like capsule that splits open to release a single seed.

Fruit type
Capsule
Fruit color
Black or brown

Tiny seeds are less than 1/16 inch across; they are dark brown or black, shiny, round in circumference, and somewhat flattened. Seeds can remain viable in the ground for at least ten years.