Pontederia sagittata
Perennial aquatic plant with lilac flowers and rhizomatous stems.
Pontederia sagittata is an aquatic perennial in the pickerel-weed family. It grows from tough, rhizomatous stems that stand upright. The basal leaves have petioles up to a meter long, which are sometimes reddish but not inflated. Leaf blades are lance-shaped, 8–32 cm long and 5–19 cm wide, with a heart-shaped base and pointed tip. The inflorescence carries over 50 flowers, arranged in clusters of three, four, or more along a thick, hairy peduncle that is 10–22 cm long. The lower spathe’s blade matches the leaf size, while the upper spathe is 3–9 cm long and open along its upper half. Each flower is about 1.5 cm across, with a lilac (rarely white) perianth that is hairy and glandular on the outside. The six perianth lobes are roughly equal in length. There are two whorls of stamens: long filaments (6–9 mm) and short ones (0.7–3.5 mm), both with glandular hairs near the tip; all anthers are yellow. The pistil is 3–6 mm long, with a hairy style and a three-lobed stigma. The fruit is a deltiform utricle 5–6 mm long with smooth ribs, containing smooth, obovoid seeds 2.3–2.5 mm long covered by a mucilaginous, oily-looking layer.
First described by Carl Presl in 1827, this species has sometimes been treated as a form or variety of *Pontederia cordata*. It has a patchy native range from Mexico through Central America to eastern and southern Brazil. It grows along riverbanks, lagoon edges, ponds, and swamps, up to elevations of 1,500 meters.
Quick Facts
- Taxon
- Pontederia sagittata
Facts from the source article.
Lore & Background
Pontederia sagittata was first described by Carl Presl in 1827. It has sometimes been reduced to a form or variety of Pontederia cordata, reflecting taxonomic uncertainty. The species 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, at altitudes of up to 1,500 m (4,900 ft).
Reader's Guide
Pontederia sagittata is a perennial aquatic plant with erect, rhizomatous tough stems. Its basal leaves have petioles up to 1 m, not inflated, sometimes reddish, and blades 8–32 cm long by 5–19 cm wide, lanceolate with a cordate base and acute apex. The inflorescence bears more than 50 flowers arranged in groups of 3, 4 or more along the peduncle, which is thick and hairy to hairy or rarely glabrous. The perianth is lilac or rarely white, externally hairy-glandular, with outer and inner lobes each about 6 mm. The plant produces utricles 5–6 mm, deltiform with smooth rib edges, and seeds 2.3–2.5 mm, smooth, obovoid, covered by a mucilaginous layer with an oily appearance. Its discontinuous distribution and taxonomic history as a possible variant of Pontederia cordata contribute to its botanical interest.
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