Habit: Ottelia alismoides is an annual or perennial herb, rooted, and completely submersed (Godfrey and Wooten 1979; Cook and Urmi-König 1984).
Stem/Roots: stem small and corm-like, occasionally forked, with fibrous roots (Cook and Urmi-König 1984).
Leaves: juvenile leaves somewhat linear, becoming oblanceolate, ovate or broadly cordate with maturity (Godfrey and Wooten 1979). Largest leaves from 11 to 16 cm long, their bases tapering to meet the petioles. Petioles of varying lengths (potentially up to 50 cm). Lower margins of leaves and edges of petioles often shallowly serrated to sharply toothed (Cook and Urmi-König 1984). Conspicuous longitudinal ribbing and cross-ribbing on the upper surface of the leaves gives a quilted effect (Cook et al. 1984).
Flowers: wrapped within spathes, cylindrical structures 2-4 cm long, composed of green bracts that are ornamented with 3 or more ruffled wings. Spathes born on long, angled stalks that become spiraled after flowering. Sepals and short-lived petals of male flowers exert from the tip of the spathe just above the water surface. Spathes containing female and/or bisexual flowers are self-fertile and remain submersed. Petals white, pink, blue or purple, often tinged with yellow at the base (Cook and Urmi-König 1984).
Fruit/Seeds: fleshy, encapsulated fruits contain as many as 2000 seeds (Cook and Urmi-König 1984).
Look-alikes: Alisma spp. (water plantain), Cryptocoryne spp. (water trumpet), Echinodorus spp. (burhead), Sagittaria spp. (arrowhead). Conspicuous cross-ribbing on the submersed leaves, and ruffled wings on flower bracts help distinguish this species (Cook et al. 1984; Cook and Urmi-König 1984).
References: (click for full references)
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This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.