Description :

• Perennial emergent herb; stem erect, 1-leaved, with several sheathing, bract-like leaves at base
• Leaves obtuse, margins entire with parallel, outwardly curved-convergent venation; blades lanceolate, ovate, cordate, sagittate, hastate or reniform; foliage dark green to greyish
• Petiole of leaf of floral shoot short; petioles of other leaves long; bases sheathing and clasping, sheaths ligulate
• Inflorescence a spike with few to many blue, white or white-green flowers, enclosed by a spathe and petiole base of leaf of floral shoot
• Flowers irregular, bilabiate, largest perianth lobe with a bilobed yellow spot
• Stamens unequal, in two groups of 3 each, adnate to perigone tube; anthers introrse, dorsifixed, versatile, dehiscing longitudinally; filaments and perigone tube covered with hairs terminating in pinhead-like glands
• Ovary with 2 carpels aborted and 1 fertile, 1-locular, 1-ovulate; ovule pendulous, anatropous; placentation parietal
• Fruit a 1-seeded, indehiscent nut, enclosed by a hardened perigone base, toothed, smooth or with spinulose ridges; pericarp rich in glutin
• Seeds reniform or ovoid; endosperm white, copious, surrounding a cylindrical embryo
• x = 8 (polyploidy)

Nomenclature:

• *Pontederia L.
  • Linnaeus: 288 (1753)
  • Cook: 194 (1990)
  • Obermeyer: 66 (1985)
  • Lowden: 449 (1973)

Distribution & Notes:

• Global : Species 4, tropical to warm America, naturalised in Australia, Europe and southern Africa
• Southern Africa : Species 1: * Pontederia cordata L. var. ovalis Solms, originally from tropical South America, is sold in local nurseries as an ornamental water plant and has become naturalised locally and may become invasive