Potamogetonaceae

Zannichellia P.Micheli ex L.

First published in Sp. Pl.: 969 (1753)
This genus is accepted
The native range of this genus is Cosmopolitan.

Descriptions

Zannichelliaceae, H. J. Beentje, M.Sc., Ph.D., F.L.S.. Flora of Tropical East Africa. 2000

Morphology General Habit
Submerged annuals or short-lived perennials, monoecious; rhizome creeping, sympodial, matted; roots 1–2 per node, unbranched, covered with root-hairs; stems simple or branched
Morphology Leaves
Leaves distally in pseudowhorls of three, proximally opposite or alternate, linear; leaf-sheath absent or short; axillary scales 2
Morphology Reproductive morphology Flowers
Flowers unisexual, solitary or more usually in groups of 1 staminate and a cluster of pistillate flowers at each pseudowhorl; staminate flowers ephemeral, long-stalked, anthers 4–8-locular, pollen globose; pistillate flowers surrounded by a spathe, solitary or pseudo-umbellate, ovary surrounded by an appressed layer (‘perianth’), style exserted, tubular, stigma ephemeral
Morphology Reproductive morphology Fruits
Fruit a drupelet, stipitate; seed with a coiled hypocotyl.
[FTEA]

J. R. Timberlake, E. S. Martins (2009). Flora Zambesiaca, Vol 12 (part 2). Royal Botanic Gardens, Kew

Morphology General Habit
Annual, rarely perennial, herbs of fresh or brackish water
Morphology Stem
Stems not clearly differentiated into rhizome and erect shoots
Morphology Roots
Roots single or in pairs at the nodes
Morphology Leaves
Leaves opposite, alternate or the furthest in pseudowhorls of 3(4), mostly less than 1 mm wide, 1(3)-veined, the furthest younger leaf with a membranous sheath free from the blade
sex Hermaphrodite
Monoecious
Morphology Reproductive morphology Inflorescences
Inflorescence usually of 1 male and 1 female flower
sex Male
Male (staminate) flowers naked; anther (2)4(8)- sporangiate; connective prolonged into a blunt appendage
sex Female
Female (carpellate)flowers with (1)4–5(8) carpels surrounded basally by a membranous tubular perianth
Morphology Reproductive morphology Flowers Gynoecium Style
Style short, less than 1 mm long; stigma asymmetric, funnel or cup-shaped, oblique-peltate with wavy margins
Morphology Reproductive morphology Fruits
Fruit an elongated drupelet, crowned by the persistent style Endocarp often with a irregularly toothed or warty ridge on the dorsal and occasionally on the ventral side
Note
Chromosome numbers 2n = 12, 24, 28, 32, 34 and 36
Distribution
Two species, 1 with a worldwide distribution (sometimes regarded as up to 6 polymorphic species) and 1 endemic to the W Cape of South Africa.
[FZ]

Sources

  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0