Description: Annual or perennial, free-floating, rhizomatous or stoloniferous aquatic herbs.
Leaves alternate, sheathed, often stipulate, often with a petiole-like stalk between the sheath and the expanded blade; blade hair-like to circular, base cuneate to cordate.
Inflorescence spike-like, paniculate or flowers solitary, subtended by 2 spathes. Flowers bisexual, sometimes heterostylous, actinomorphic or zygomorphic. Perianth lobes usually 6, variously fused, petaloid, white, blue or yellow. Stamens 6, 3 or 1, similar or dissimilar, inserted on perianth; anthers 2-locular, introrse, dehiscing by longitudinal slits or rarely apical pores. Ovary superior, 3-locular though sometimes only 1 fertile; style 1.
Fruit a capsule or 1-seeded nutlet; seeds numerous or solitary.
Distribution and occurrence: World: 9 genera, c. 40 species, America, Africa, Asia, Australia. Australia: 3 genera, 6 species, all mainland States.
Angiosperm Phylogeny Website (Family: Pontederiaceae, Order: Commelinales)
Text by S. W. L. Jacobs
Taxa not yet included in identification key
| ||Key to the genera|| |
|1||Plants mostly free-floating; flowers more than 3 cm across||Eichhornia|
|Plants mostly rooted; flowers, less than 3 cm across||2|
|2||Fruit 3-locular with many seeds; perianth free almost to base||Monochoria|
|Fruit a 1-seeded nutlet; perianth fused for half its length, 2-lipped, the upper lip with 3 lobes fused for about half their length, the lower lip with 3 lobes almost free from each other|
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