Family: Potamogetonaceae |
Roots single or in pairs at nodes. Leaves: blade entire, veins 1[--3], nearly terete. Inflorescence usually of 2 flowers, 1 staminate, 1 pistillate. Flowers short-pedicellate. Staminate flowers: anthers 4-loculed. Pistillate flowers: pistils surrounded proximally by membranaceous envelope; stigma asymmetrically funnel-shaped. Fruits: convex margin minutely dentate; endocarp often coarsely papillose (visible after decay of outer fruit wall); stipe developing into podogyne (stalk supporting pistil). Fls paired, one of each sex on an axillary, bifurcated common stalk; perianth none; filament elongate; anther with (1)2(4) thecae and (2)4(8) microsporangia; pistillate fl subtended by a minute, membranous, initially closed cupule; ovaries (1-)4 or 5(-9), distinct, each with a slender style and peltate-funnelform stigma; fr a short- stipitate achene or drupelet with a warty dorsal ridge, terminated by the persistent, beak-like style; most lvs opposite, but the distal ones in seeming whorls of 3 or 4, the prominent, stipule- like sheath completely wrapped around the stem but free from the slender blade. Monotypic.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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