Common duckweed

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Common duckweed

Common duckweed

Common duckweed

Common duckweed

Morphology

Stem

Stems absent. Roots 1 per thallus, to 3/5 inch, tip mostly rounded; sheath not winged at base.

Leaves

Leaves not clearly differentiated. Thallus 1 or in clusters of 2-5 or more, usually not reddish on lower surfaces, or if reddish, much less so than on upper surfaces, nearly round to elliptic or obovate, 1/12 to 1/6 inch long, 2--4 x 1/16 to 1/8 inch wide, lower surface slightly convex, upper surface convex or sometimes with an indistinct papilla, veins 3(-5), obscure, greatest distance between lateral veins near or proximal to middle of thallus.

Inflorescence

Inflorescences highly reduced and consisting of 1-2 staminate and 1 pistillate flowers sometimes subtended by a tiny membranous sheath, rarely produced in nature in some species, plants reproducing mosty asexually through formation of plantlets in pouches along margins of tallus.

Flower

Flowers seldom observed, unisexual, 1(-2) per thallus; sepals absent, petals absent; stamens 1-2; pistil 1.

Fruit

Utricles; seeds 1-3, with 8-15 distinct ribs, remaining in fruit wall after ripening.

Ecology

Habitat

Ponds and lakes, marshes, backwater areas along rivers and streams, springs and spring runs

Distribution

Occurs statewide

Additional Notes