Description :

• Small, delicate, often submerged aquatic or terrestrial herbs with limited vascular system; monoecious
• Leaves opposite, small, entire; stipules 0
• Flowers unisexual, small, axillary, solitary, rarely a male and female flower from the same leaf axil forming an apparently bisexual flower; bracts caducous; perianth absent
• Male flowers : stamen 1; filament filiform, elongated or shorter than ovary; anther 2-thecous, opening by longitudinal slits joining at the top
• Female flowers : ovary superior, 2(-4)-locular, (2-)4-furrowed and -lobed, sessile or shortly stalked, with a single, pendulous, axile, anatropous, unitegmic ovule in each locule; styles 2, longer or shorter than ovary, papillose on either side
• Fruit leathery, compressed, indehiscent, with lobes dorsally margined or winged, 2(-4)-seeded
• Seeds with oily endosperm
• x = 5 (3, 4, 14, 19) (polyploidy)

Nomenclature:

• Callitriche L.
  • Linnaeus: 969 (1753)
  • Marloth: 141 (1925)

Distribution & Notes:

• Global : Species ± 25, cosmopolitan
• Southern Africa : Species 2, Namibia, KwaZulu-Natal and Western Cape