Source:
SSA
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).
Distribution:
Species 4, tropical to warm America, naturalised in Australia, Europe and sthn Afr.: * 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.
Classification:
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