Description:

• Herbs, aquatic, monoecious or flowers sometimes bisexual
• Leaves alternate, opposite, or whorled, entire to variously dissected and pectinate-pinnate
• Flowers unisexual or bisexual, axillary, solitary, sessile or shortly pedicelled, or in a terminal spike with male flowers above and female below; bracts leafy; bracteoles 2, concave
• Male flowers: calyx entire or 2-4-lobed, tube very short; petals 2-4, elliptic, concave; ovary 0; styles 4, rudimentary; stamens 2-8, exserted, filaments thread-like, anthers linear to linear-oblong
• Female flowers: calyx entire or 4-lobed, tube sometimes furrowed; petals minute or 0; stamens 0 or rudimentary; ovary 2- or 4-locular, with a solitary, pendulous ovule in each locule, styles 4, short, thick and fleshy, often recurved, plumose or glandular-hairy
• Fruit a nut or drupe or of 4 indehiscent carpels
• x = 7 (9) (polyploidy)

Nomenclature:

• Myriophyllum L.
  • Linnaeus: 992 (1753)
  • Harvey: 572 (1862)
  • Mendes: 77 (1978)

Distribution & Notes:

• Global: Species 40, cosmopolitan, represented in Africa south of the Sahara by 2 species only, probably both introduced
• Southern Africa: Namibia, Botswana, Northern Province, North-West, Gauteng, Mpumalanga, Free State, KwaZulu-Natal, Northern, Western and Eastern Cape