Pontederia sagittata is a species of aquatic plant belonging to the family Pontederiaceae.
It is a perennial plant with erect, rhizomatous tough stems. Basal leaves, emerging; pods 10–27 cm, the apex emarginate; petioles up to 1 m, not inflated, sometimes reddish; Blades 8-32 x 5–19 cm, lanceolate, the base cordate, the apex acute. Inflorescence with more than 50 flowers; flowers arranged in groups of 3, 4 or more along the peduncle, sessile; peduncle (6-)10-20(-22) cm, thick, hairy to hairy or rarely glabrous; internode between spathes (3.5-)5-16(-20) cm; blade of lower spathe 8-32 x 5–19 cm; upper spathe (3-)4-7(-9) cm, open on the upper 1/2, the apex mucronulate. 1.5 cm flowers. Perianth lilac or rarely white, externally hairy-glandular; outer lobes c. 6mm; internal lobes c. 6mm Long filaments 6–9 mm, with glandular hairs in the upper 1/3, short ones 0.7-3.5 mm, with glandular hairs in the upper 1/3; anthers of upper whorl 0.75–1 mm, yellow; anthers of lower whorl 0.55-0.85 mm, yellow. Pistil 3–6 mm; style hairy towards apex; stigma 3-lobed. Utricles 5–6 mm, deltiform, with smooth rib edges; seeds 2.3-2.5 mm, smooth, obovoid, covered by a mucilaginous layer with an oily appearance.
Pontederia sagittata was first described by Carl Presl in 1827. It has sometimes been reduced to a form or variety of Pontederia cordata.
Pontederia sagittata has a discontinuous distribution, being native from Mexico to Central America and then eastern and southern Brazil. It is found on the edges of rivers, lagoons, ponds, and swamps,[1] at altitudes of up to .