Aponogeton rehmannii Oliv.

First published in Hooker's Icon. Pl. 15: t. 1471B (1884)
This species is accepted
The native range of this species is Kenya to S. Africa. It is a tuberous hydrogeophyte and grows primarily in the seasonally dry tropical biome.

Descriptions

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/185487/84262580

Conservation
LC - least concern
[IUCN]

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

Type
Type South Africa, Northwest Province (Transvaal), Boshveld, between Kleinsmit and Kameelpoort, 1875, Rehmann 4835 (K holotype, Z).
Morphology General Habit
Perennial herb with tuber elongate or ovoid, up to 5 cm long and 0.8–2.5 cm in diameter, usually densely set with whitish roots in upper part
Morphology Leaves
Leaves few to many, the primary ones submerged, usually linear or sword-shaped, sometimes with a spathulate or oblanceolate blade, sessile, the secondary ones with a floating blade; petiole 3–15(30) cm long and up to 3 mm thick; blade 2–10 cm long and 4–18 mm wide, narrowly ovate or linear-lanceolate, cuneate, obtuse, rounded or truncate at base, subacute or obtuse and apiculate at apex, with 2–3 weak longitudinal parallel nerves on each side of the prominent midrib
Morphology Reproductive morphology Inflorescences Peduncles
Peduncle 5–15(30) cm long and up to 2 mm thick, not thickened towards apex; spathe 6–10 mm long, early caducous
Morphology Reproductive morphology Inflorescences
Spikes 2, very densely flowered, 4–15 mm long, up to 50 mm long in fruit
Morphology Reproductive morphology Flowers
Flowers bisexual or female, arranged all around rachis
Morphology Reproductive morphology Flowers Tepal
Tepals 1–2, white or rarely pinkish, 1.5–3 × 0.8–2 mm, ovate to obovate, 1-nerved
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 6 (0 in apomictic plants); filaments up to 3 mm long, slightly widened towards base; anther mauve or purple with yellow pollen
Morphology Reproductive morphology Flowers Gynoecium Carpels
Fruiting carpels up to 5 mm long and 3 mm wide with a whitish beak Carpels 3 (up to 6 in apomictic plants), each with 2–6 ovules
Morphology Reproductive morphology Seeds
Seeds usually 2–4 on each carpel, 2–3 mm long, narrowly ovoid or cylindrical, slightly curved; testa simple, brown; plumule absent.
Distribution
Caprivi, Botswana, Zimbabwe. Reported also from Kenya, Namibia and South Africa.
Ecology
In seasonal pools and small pans, flooded plains, in muddy or sandy wet soils; 900–1160 m (to 1700 m outside the Flora area).
Conservation
Conservation notes Widespread species; not threatened.
[FZ]

Aponogetonaceae, K.A. Lye (Agricultural University of Norway). Flora of Tropical East Africa. 1989

Morphology General Habit
Plants monoecious.
Vegetative Multiplication Tubers
Tuber oval or irregularly shaped, 15–40 mm. long and 10–25 mm. thick, densely set with white or brownish roots in upper part.
Morphology Leaves
Leaves few–many (usually 5–10 fresh leaves per plant); petiole 3–30 cm. long and 1–3 mm. thick, usually prominent, but occasionally soft juvenile linear leaves without stalk and blade are produced; blade usually floating on the surface of the water, oval to linear-lanceolate, 3–10 cm. long and 0.3–2.5 cm. wide (East African plants have 3–8 mm. wide blades), with apiculate or subacute tip and cuneate or somewhat rounded base, sometimes strongly attenuate; midrib prominent and with 2–3 weak parallel nerves on each side of the midrib.
Morphology Reproductive morphology Flowers
Flowers white, densely set in bifid spikes with the flowers facing in all directions; penducles 5–30 cm. long and 0.5–2 mm. thick, green to olive-brown with white or purplish base, not thickened below the inflorescence; spathe up to 10 mm. long, very early caducous.
Morphology Reproductive morphology Inflorescences
Spikes bisexual, densely-flowered, 0.5–2.5 cm. long and 4–6(–9 in fruit) mm. wide.
Morphology Reproductive morphology Flowers Tepal
Tepals 1–2, white or with a faint pinkish tinge, ovate or obovate, 2–4 mm. long and 0.7–2 mm. wide, 1-nerved.
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 6, but often lacking since the plants are often apomictic.
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovaries 3–6, grey to purplish when young; ovules 2–6.
Morphology Reproductive morphology Fruits
Follicles 5–6 mm. long and ± 3 mm. wide, greyish brown with whitish beak.
Morphology Reproductive morphology Seeds
Seeds cylindrical, straight or slightly curved, 2.5–3.8 mm. long and 0.8–1.2 mm. wide, greyish green, without longitudinal ridges; testa simple.
Habitat
Seasonal pools in rock pavement, or other temporary gatherings of water; 1450 m.
Distribution
K4 but not yet found in Tanzania
[FTEA]

Common Names

English
Pondweed

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0
  • 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

  • IUCN Categories

    • IUCN Red List of Threatened Species
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • 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
  • 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/