Hydrocharitaceae
Lagarosiphon

Lagarosiphon cordofanus Casp.

First published in Jahrb. Wiss. Bot. 1: 504 (1858)
This species is accepted
The native range of this species is Cameroon to Ethiopia and Namibia. It is a hydrosubshrub and grows primarily in the wet tropical biome.

Descriptions

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

Type
Type Sudan, ‘Arasch-Cool’, Kotschy 170 (B† holotype, G lectotype selected by Symoens & Triest (1983), BM, K, L, MPU, P, Z).
Morphology General Habit
Perennial herb
Morphology Stem
Stems filiform, up to 2.5 m long and 0.5–2 mm wide
Morphology Leaves
Leaves alternate, subopposite or locally whorled, spreading, linear, (5)7–20(29)           0.3–1(1.5) mm, soft, thin, transparent, apex tapering to very acute; epidermal cells predominantly elongate; margins green, without sclerenchyma fibres, each with (15)25–50(66) teeth situated on triangular protuberances, somewhat curved, pointing upwards, sharp; central area broad, rarely narrow, with larger cells, usually with 2 longitudinal air-spaces divided by transverse septa and 2 parallel fibre lines
Morphology General Scales
Intravaginal scales colourless, ovate or narrowly ovate, apex with 1–4 papillae
sex Male
Male inflorescence with spathe containing 7–14 flower buds, valves ovate to broadly ovate, 1.3–2.7 1–2.1 mm, bearing 3–16 teeth; male flowers whitish, perianth segments c.1 mm long; stamens c.2 mm long, anther with pointed tip
sex Female
Female inflorescence with spathe valves ovate to narrowly ovate, 1.7–2.8 0.7–1.2 mm, entire or bearing up to 10 teeth; female flowers whitish, perianth segments obovate, 0.7–1 c.0.5 mm; ovary with 10–40 ovules
Morphology Reproductive morphology Fruits
Capsule ovoid, tapered above, 3–4 1.5–2 mm, pericarp honeycombed when dried
Morphology Reproductive morphology Seeds
Seeds narrowly ellispoid, 1–1.5 0.3–0.5 mm.
Distribution
Botswana, Zambia, Zimbabwe, Malawi, Mozambique. Widespread in the Sudano-Zambezian Region; also in Cameroon, Sudan, Ethiopia, Somalia, Congo (Katanga), Rwanda, Uganda, Kenya, Tanzania, Angola, Namibia and the northern provinces of South Africa.
Ecology
In lakes, dams, ponds, swamps and on floodplains in permanent or temporary pools, also in slow-flowing freshwater with water depth 0.15–2 m; 100–1050 m.
Conservation
Conservation notes Widespread species; not threatened.
Recognition
Lagarosiphon cordofanus is a very variable species, well characterized by the leaf having a broad central area, usually with 2 longitudinal air-spaces and 2 parallel fibre lines, and marginal teeth situated on triangular protuberances. Some specimens from the Bangweulu–Luapula area with linear, narrow leaf (1–1.2 mm wide) and a distinct midrib, but without the two fibre lines, could represent a hybrid between L cordofanus and L. ilicifolius
[FZ]

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

Morphology Stem
Stems filiform
Morphology Leaves
Leaves spirally arranged or in whorls, linear to narrowly linear-lanceolate, 4–30 x 0.25–1(–1.8) mm, acute, spreading or recurved, with green margins but with a broad band of sclerenchyma fibres along either side of midrib
Morphology Reproductive morphology Inflorescences Bracts Spathe
Male spathe 1.3–2.7 mm long, containing 7–14 flowers
Morphology Reproductive morphology Flowers
Male flowers white; tepals c. 1 mm long; perianth tube up to 50 mm long; stigmas c. 1.5 mm long, purplish
Morphology Reproductive morphology Fruits
Capsule ovoid, 2.5–4 mm long
Morphology Reproductive morphology Seeds
Seeds 1–1.5 mm long.
Distribution
C2; S1, 3 widespread in tropical and southern Africa.
Ecology
Altitude range 30–230 m.
[FSOM]

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/185529/120203981

Conservation
LC - least concern
[IUCN]

Hydrocharitaceae, David Simpson. Flora of Tropical East Africa. 1989

Morphology General Habit
Stems filiform or terete, 0.2–2 mm. in diameter, whitish to mid-green.
Morphology Leaves
Leaves spirally arranged to subopposite or in whorls, linear to narrowly linear-lanceolate, shortly to narrowly acute, light to dark green, patent, spreading or somewhat recurved, flaccid, translucent, 4–29 mm. long, 0.25–1(–1.8) mm. wide, with 2 broad bands of sclerenchyma fibres along either side of midrib; submarginal fibres absent; margins green, denticulate, the teeth usually curved towards the leaf-apex and with a triangular green base.
Morphology General Scales
Nodal scales ovate to broadly ovate, the margins entire.
Morphology Reproductive morphology Inflorescences Bracts
Male spathe ovate to broadly ovate, 1.3–2.7 mm. long, 1–2 mm. wide, pinkish white, containing 7–14 flowers. Female spathe narrowly ovate to ovate, 1.7–2.8 mm. long, 0.7–1.2 mm. wide.
sex Male
Male spathe ovate to broadly ovate, 1.3–2.7 mm. long, 1–2 mm. wide, pinkish white, containing 7–14 flowers. Male flowers:sepals and petals elliptic, ± 1 mm. long, 0.3–0.5 mm. wide, white, translucent; stamens ± 2 mm. long.
Morphology Reproductive morphology Flowers
Female flower:sepals and petals elliptic to obovate, 0.7–1.2 mm. long, 0.5–0.8 mm. wide, white, translucent; ovary ± 2 mm. long, with 10–40 ovules; perianth-tube up to 50 mm. long; stigmas 1.3–1.7 mm. long, purplish. Male flowers:sepals and petals elliptic, ± 1 mm. long, 0.3–0.5 mm. wide, white, translucent; stamens ± 2 mm. long.
sex Female
Female flower:sepals and petals elliptic to obovate, 0.7–1.2 mm. long, 0.5–0.8 mm. wide, white, translucent; ovary ± 2 mm. long, with 10–40 ovules; perianth-tube up to 50 mm. long; stigmas 1.3–1.7 mm. long, purplish. Female spathe narrowly ovate to ovate, 1.7–2.8 mm. long, 0.7–1.2 mm. wide.
Morphology Reproductive morphology Fruits
Fruit ovoid, 2.5–4 mm. long, 1.5–2 mm. wide.
Morphology Reproductive morphology Seeds
Seeds narrowly ellipsoid, 1–1.5 mm. long, 0.3–0.5 mm. wide, brown.
Figures
Fig. 1.
Habitat
Still or slow-flowing freshwater; 0–1700 m.
Distribution
K1 K4 K6 K7 T1 T2 T3 T5 T6 T7 T8 U3 Z also central and southern Africa
[FTEA]

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 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

    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • 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/