Northern Prairie Wildlife Research Center
Northeast Wetland Flora
Field Office Guide to Plant Species
Polygonum aviculare L.
- Family: Smartweed (Polygonaceae)
- Flowering: June-November
- Field Marks: This species is recognized by its tiny axillary flowers, its dull (not shiny)
achenes, and its sprawling growth form.
- Habitat: Disturbed soil.
- Habit: Annual herb from a taproot, frequently mat-forming.
- Stems: Lying flat, branched, wiry, slightly grooved, smooth, up to 2 feet long.
- Leaves: Alternate, simple, broadly elliptic to oval to oblong, rounded or pointed at the tip, tapering to the base, without teeth, green to pale green to blue-green, up to 1 1/4 inches long, up to 1/3 inch wide, sessile or nearly so; sheaths silvery, shredded.
- Flowers: 1-5 in the axils of the leaves, sessile or on very short stalks.
- Sepals: 5, united below, usually green with pink or white borders, up to 1/8 inch long.
- Petals: 0.
- Stamens: 5-8.
- Pistils: Ovary superior.
- Fruits: Achenes triangular to somewhat compressed, ovoid, pointed at the tip, dark brown, shiny only along the margins, striate to granular to minutely dotted, up to 1/8 inch long.
- Notes: This is a noxious weed in lawns and in the cracks of sidewalks.
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