Northern Prairie Wildlife Research Center
Northeast Wetland Flora
Field Office Guide to Plant Species
Polygonum arifolium L.
- Family: Smartweed (Polygonaceae)
- Flowering: July-October
- Field Marks: This species is readily recognized by its hastate leaf shape and the presence of
reflexed prickles on the stems.
- Habitat: Marshes, swamps.
- Habit: Sprawling perennial from fibrous roots.
- Stems: Spreading, often lying on other vegetation, 4-angled, reflexed prickly, up to 6 feet long.
- Leaves: Alternate, simple, hastate, pointed at the tip, truncate to slightly heart-shaped at the base, up to 8 inches long, up to 6 inches wide, stellate-hairy at least on the lower surface, prickly on the main veins below, the lowermost leaves on prickly stalks, the uppermost leaves sessile or nearly so; sheaths fringed at summit, bristly-hairy at the base.
- Flowers: Few in short terminal or axillary racemes, the racemes with glandular-bristly stalks.
- Sepals: 5, pink to white to greenish, united below, up to 1/8 inch long.
- Petals: 0.
- Stamens: 6.
- Pistils: Ovary superior; style 2-parted.
- Fruits: Achenes lenticular, obovoid, dark brown, smooth, shining, up to 1/6 inch long.
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