Pontederiaceae

Pontederia L.

First published in Sp. Pl.: 288 (1753)
This genus is accepted
The native range of this genus is Cosmopolitan.

Descriptions

Pontederiaceae, B. Verdcourt. Flora of Tropical East Africa. 1968

Morphology General Habit
Floating or creeping aquatic herbs, rooting at the nodes
Morphology Leaves
Leaves often of two sorts, the floating or erect ones broad, lanceolate, ovate or orbicular, the submerged ones linear; petioles long, sheathing at the base or sheath produced at apex to form a “stipule”
Morphology Reproductive morphology Flowers
Flowers solitary or in spikes or panicles arising from a convolute sheath-like spathe or bract, or fasciculate within the leaf-sheath
Morphology Reproductive morphology Flowers Perianth
Perianth funnel-shaped, slightly irregularly divided into 6 lobes, the inner broader than the outer
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 6, the 3 upper included, the 3 lower ± exserted, usually with longer filaments
Morphology Reproductive morphology Flowers Gynoecium Pistil
Ovary 3-locular; ovules numerous; style filiform; stigma entire or very shortly 3–6-lobed
Morphology Reproductive morphology Fruits
Capsule membranous, 3-locular, enclosed in the faded perianth, ovoid to linear-fusiform
Morphology Reproductive morphology Seeds
Seeds numerous, oblong or ellipsoidal, finely ribbed.
[FTEA]

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit
Plants floating or rooted in mud
Morphology Leaves
Leaves with slender, stout or inflated petioles and flat blades, or sometimes completely narrow and grass-like when submerged
Morphology Reproductive morphology Flowers
Flowers solitary to numerous; perianth conspicuous, somewhat 2-lipped, the 6 parts in 2 series, all united into a tube below
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 6, 3 included and 3 exserted
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary 3-celled; ovules numerous. Fruit a many-seeded capsule.
Distribution
About 5 species, natives of tropical America.
[Cayman]

Pontederiaceae, B. Verdcourt. Flora of Tropical East Africa. 1968

Morphology General Habit
Erect glabrous usually perennial aquatic herbs, sometimes with stems arising from a stout creeping rhizome
Morphology Leaves
Leaves all radical with long petioles; flowering stems radical, each bearing one apical sheathing leaf, its petiole appearing as a prolongation of the stem
Morphology Reproductive morphology Flowers
Flowers medium-sized, blue, pedicellate, arranged in racemes (sometimes subumbelliform); the inflorescence is at first enclosed in a membranous spathe at the base of the peduncle, contained in the sheath of the apical leaf
Morphology Reproductive morphology Flowers Perianth
Perianth-lobes 6, free almost to the extreme base, the inner 3 broader, at first spreading, later twisted
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 6, fixed on the base of the perianth, equal or usually unequal, 5 with smaller yellow anthers, the sixth with a longer filament bearing an erect lateral tooth and having a longer blue anther
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary 3-locular; ovules numerous
Morphology Reproductive morphology Flowers Gynoecium Pistil
Style filiform; stigma subentire or very shortly 3–6-fid
Morphology Reproductive morphology Fruits
Capsule loculicidally splitting into 3 valves
Morphology Reproductive morphology Seeds
Seeds oblong, longitudinally ribbed.
[FTEA]

Sources

  • Flora of Tropical East Africa

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

  • Flora of the Cayman Islands

    • Flora of the Cayman Islands
    • 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.

  • Interactive Key to Seed Plants of Malesia and Indo-China

    • The Malesian Key Group (2010) Interactive Key to Seed Plants of Malesia and Indo-China (Version 2.0, 28 Jul 2010) The Nationaal Herbarium Nederland Leiden and The Royal Botanic Gardens Kew

  • 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