Description: Submerged dioecious or monoecious rhizomatous aquatic salt- tolerant annuals or perennials with slender capillary stems.
Leaves opposite, pseudowhorled or alternate, linear, simple, entire; sheathing bases present, ligulate, the ligule sometimes longer than the sheath.
Flowers unisexual, axillary, solitary or clustered. Perianth cup-like, reduced to a few small scales or absent. Stamens 1–3, fused if more than 1 into a single anther mass, 4-, 8- or 12-sporangiate; pollen globose. Ovary of 1–9 free carpels; style simple, usually persistent; stigma conspicuous, funnel-shaped to spathulate; ovule 1, pendulous.
Fruit a nutlet.
Distribution and occurrence: World: 4 genera, 8–12 species, Australia & New Zealand. Australia: 2 genera, 7 species (native), all States except N.T.
Angiosperm Phylogeny Website (Family: Potamogetonaceae, Order: Alismatales)
Text by S. W. L. Jacobs
| ||Key to the genera|| |
|1||Ligule longer than the sheath; leaves usually opposite; female flower with cup-like perianth||Zannichellia|
|Ligule shorter than the sheath; leaves mostly alternate but leaves subtending flowers may be opposite; female flowers with 3 distinct perianth segments||Lepilaena|