Potamogetonaceae

Potamogeton L.

First published in Sp. Pl.: 126 (1753)
This genus is accepted
The native range of this genus is Cosmopolitan.

Descriptions

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

Morphology General Habit
Aquatic herbs
Vegetative Multiplication Rhizomes
Rhizome present or absent, if present well differentiated from the stem, filiform, slender or robust, terete or ± compressed; stem terete or compressed, unbranched or ± densely branched; turions present or absent
Morphology Leaves
Leaves alternate, but mostly subopposite toward the inflorescence apex (involucral leaf), sessile or petiolate, 1- to many-nerved, all submerged and with filiform, grass-like or an expanded blade, or dimorphic, the submerged ones thin and ± translucent, sometimes reduced to phyllodes, the floating ones ± coriaceous, opaque, petiolate, and usually broader; stipules always present although sometimes disintegrating or falling early, sheathing the stem and/or axilllary bud, closed or convolute, mostly free from leaf, rarely fused for less than half its length with the leaf base
Morphology Reproductive morphology Inflorescences
Spikes cylindrical or subglobose, 3 to many-flowered, dense or sometimes interrupted, mostly borne above the water and wind- pollinated, but sometimes submerged and water-pollinated
Morphology Reproductive morphology Flowers Tepal
Tepals rounded at apex
Morphology Reproductive morphology Fruits
Fruitlets rounded on back, with soft mesocarp and multi-layered sclerified endocarp, with or without a distinct beak
Morphology Reproductive morphology Seeds Embryo
Embryo hooked-shaped or spiral
Distribution
A cosmopolitan genus with about 60 species and 46 hybrids.
[FZ]

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Slender to robust aquatic plants surviving cold or dry periods by rhizomes or specialized buds borne either on the rhizome or on the leafy stem
Morphology Leaves
Submerged leaf-blades usually thin and translucent, linear and grass-like to oblong, 1–many-nerved; floating leaf-blades usually more coriaceous and opaque; stipules either free from the leaf-bases or adnate to them in their lower part (stipular sheath) and free above (ligule), in either case the basal part may be open or tubular
Morphology Reproductive morphology Inflorescences
Spikes cylindrical to ovoid, dense or lax, sometimes interrupted, either raised a little above the water and wind-pollinated or submerged and water-pollinated
Morphology Reproductive morphology Flowers Tepal
Tepals rounded, with a stalk (clawed), green or brownish
Morphology Reproductive morphology Fruits
Fruit brown or greenish, often asymmetric.
Note
About 160 species
Ecology
Only few species in dry and saline regions.
[FSOM]

Potamogetonaceae, J.J. Symoens. Flora of Tropical East Africa. 2006

Morphology General Habit
Rhizome present or absent, if present well differentiated from the stem, filiform, slender or robust, terete or ± compressed; stems terete or compressed, ± densely branched; turions present or absent
Morphology Leaves
Leaves alternate, but mostly subopposite toward the inflorescence apex (involucral leaves), sessile or petiolate, 1- to many-nerved, all submerged and with filiform, grass-like or ± expanded blade, or dimorphic, the submerged ones thin and ± translucent, sometimes reduced to phyllodes, the floating ones ± coriaceous, opaque, petiolate,and usually broader; stipulesalways present,although sometimes fugacious, forming a sheath, connate or convolute around the stem; blade or petiole sometimes attached near the top of the sheath which projects beyond the joint as a ventralligule, sometimes attached farther down the sheath or arising from the node
Morphology Reproductive morphology Inflorescences
Spikes cylindrical or subglobose, 3- to many-flowered, dense or lax, sometimes interrupted, mostly borne above the water and wind-pollinated, but sometimes submerged and water-pollinated
Morphology Reproductive morphology Flowers Tepal
Tepals rounded at the apex
Morphology Reproductive morphology Fruits
Fruitlets with soft mesocarp and multi-layered sclerified endocarp, with or without a distinct beak
Morphology Reproductive morphology Seeds
Embryo unciform or spiral; cotyledon curved in the seed.
[FTEA]

Sources

  • Flora Zambesiaca

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

  • Flora of Somalia

    • Flora of Somalia
    • 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

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. 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 2024. 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

  • Neotropikey

    • Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.
    • http://creativecommons.org/licenses/by/3.0

  • Plants and People Africa

    • Common Names from Plants and People Africa http://www.plantsandpeopleafrica.com/
    • © Plants and People Africa http://www.plantsandpeopleafrica.com http://creativecommons.org/licenses/by/3.0/