Aquatic and Wetland Vascular Plants of the Northern Great Plains
Alisma L. -- Water plantain
Submersed to completely emersed perennials, cormose, fibrous-rooted and lacking rhizomes. Leaves variable depending upon the degree of submergence; emersed or floating leaf blades ovate, lanceolate or oblong-elliptic, never sagittate; submersed leaves often phyllodial, long-linear and ribbonlike (A. gramineum). Inflorescence a compound panicle, the branches and pedicels whorled, each whorl subtended by 3-several bracts. Flowers all perfect; sepals persistent, not reflexed; petals white or pinkish; stamens 6(9); pistils 10-20. Achenes in a single whorl on a flat receptacle, brown at maturity, grooved on the back, the style beak minute or absent.
References:
Fernald, M. L. 1946. North American representatives of Alisma plantago-
aquatica. Rhodora 48:86-88.
Hendricks, A. J. 1957. A revision of the genus Alisma (Dill.) L.
Amer. Midl. Naturalist 58:470-493.
Pogan, E. 1963. Taxonomical value of Alisma triviale Pursh and A.
subcordatum Raf. Can. J. Bot. 41:1011-1013.
| Lead | Characteristic | Go To |
| 1 | Leaf blades lanceolate to oblong-elliptic or absent when submersed, the leaves then consisting of long, ribbonlike phyllodes; petals usually pinkish, 1-2.5 mm long; mature achenes with a central ridge and 2 lateral ridges down the back. | A. gramineum |
| 1 | Leaf blades ovate to broadly lanceolate; petals white or very slightly pinkish, 1-4 mm long; mature achenes with a central groove and 2 lateral ridges down the back. | A. plantago-aquatica |
Return to Family -- Alismataceae - The Water Plantain Family
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