Northern Prairie Wildlife Research Center
Northeast Wetland Flora
Field Office Guide to Plant Species
Alisma subcordatum Raf.
- Family: Water-plantain (Alismataceae)
- Flowering: June-September
- Field Marks: The features that distinguish this water-plantain from others are the tiny petals
less than 1/10 inch long and the elliptic to ovate leaves.
- Habitat: Wet areas, often in standing water.
- Habit: Perennial herb with tufts of fibrous roots.
- Stems: Upright, unbranched except in the inflorescence, smooth, up to 2 feet tall, bearing a
panicle of flowers but no leaves.
- Leaves: Basal, elliptic to ovate, more or less pointed at the tip, slightly heart-shaped to
tapering at the base, without teeth, smooth, up to 4 inches long, up to 2 inches wide; leaf
stalks longer than the blades.
- Flowers: Numerous, in terminal panicles on a leafless stem, the panicle up to 1 foot long,
the branches subtended by bracts; bracts lanceolate.
- Sepals: 3, green, free from each other, rounded at the tip, up to 1/8 inch long.
- Petals: 3, white, free from each other, up to 1/8 inch long.
- Stamens: 6-9.
- Pistils: 10-25 per flower, free from each other, arranged in a single ring.
- Fruits: Achenes several in a small ring, flattened, up to 1/10 inch long, the ring of achenes
up to 1/6 inch across.
- Notes: The achenes are eaten by waterfowl.
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