Cyperaceae
Rhynchospora

Rhynchospora angolensis Turrill

First published in Bull. Misc. Inform. Kew 1914: 136 (1914)
This species is accepted
The native range of this species is Tropical Africa, Madagascar. It is a perennial or rhizomatous geophyte 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]

J. Browning, K.D. Gordon-Gray†, M. Lock, H. Beentje, K. Vollesen, K. Bauters, C. Archer, I. Larridon, M. Xanthos, P. Vorster, J. Bruhl, K. Wilson and X. Zhang (2020). Flora Zambesiaca Volume: 14: Cyperaceae. M.Á. García, J.R. Timberlake (Eds). Kew Publish

Type
Angola, Benguella, country of Ganguellas and Ambuellas, n.d., Gossweiller 3268 (K holotype).
Morphology General Habit
Perennial herb, slender to tufted, erect, 120 cm tall; rhizome contracted, almost lacking
Morphology Leaves
Leaves radical, blade to 50 × 1–3 cm, several cauline, size reduced upwards
Morphology Culms
Culm glabrous, rounded with longitudinal ridges
Morphology Reproductive morphology Inflorescences
Inflorescence a compound, corymbose cyme with several to 1 lateral cymes from upper culm nodes; corymbs loose or compact, sometimes reduced to quasi-terminal heads
Morphology Reproductive morphology Inflorescences Bracts
Bracts several, leaf-like
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets few to many per cyme, 5–8(12) × 1.8–3.5(5) mm, each maturing 2–4 nutlets; florets bisexual, glumes spiralled, rachilla straight
Morphology Reproductive morphology Flowers Perianth
Perianth bristles 5–6 (usually 6), of uniform length, 3–3.5 mm long, generally up to and beyond apex of crown
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 2
Morphology Reproductive morphology Flowers Gynoecium Style
Style deeply bifid
Morphology Reproductive morphology Fruits
Nutlet 4.1–4.4 (including style base) × 1.2–1.4 mm, elliptic to ovoid, surface transversely rugose to rugulose; style base conical, 1.2–1.7 mm long, attached throughout width.
Distribution
Zambia, Zimbabwe. Also in Cameroon, Central African Republic, D.R. Congo, Uganda, Tanzania, Angola and Madagascar.
Ecology
Marshes, near streams and in boggy grassland; 1000–1600 m.
Recognition
This species differs from the variable Rhynchospora brownii in its glabrous rounded culms and larger spikelets and nutlets. Examination of bristle length on the nutlets is needed to distinguish R. angolensis from R. brownii. Rhynchospora angolensis has numerous ‘transparent hairs’ attached at the base of the perianth segments (bristles); these are sometimes present in R. brownii. It may not be possible to easily distinguish the two species in the field, and both may be collected together, as in Robinson 2225a,b.
[FZ]

Cyperaceae, K Hoenselaar, B. Verdcourt & H. Beentje. Hypolytrum, D Simpson. Fuirena, M Muasya. Flora of Tropical East Africa. 2010

Type
Type: Angola, Benguella, country of the Ganguellas and Ambuellas, Gossweiler 3268 (K!, holo. & iso.)
Morphology General Habit
Leafy, up to 105 cm high, with a short rhizome. Perennial, slender.
Morphology Culms
Culms many, crowded, rounded with longitudinal ridges, 24–90 cm long, 0.5–0.9 mm wide, glabrous, their bases covered with scales and old leaf bases split by the new shoots and some desintegrating into fibres
Morphology Leaves
Leaf sheath brown, 2.5–7.5 cm long. Leaves up to 40 cm. Leaves subtending the primary branches. Leaf blade linear, stiff, erect, flat or triangular, 22–34 cm long, 0.6–1.8 mm wide, glabrous, the margins and apex sometimes scabrid, apex acuminate
Morphology Reproductive morphology Inflorescences
Inflorescence a slender panicle, 13–28 cm long, with main branches protruding from the upper leaf sheaths and ending in a few usually stalked and solitary spikelets.
Morphology Leaves Leaf sheaths
Sheath 1.5–3.2 cm long, blade 1.5–5 cm long, 0.6–1 mm wide.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets ovoid, acute, 5–8(–12) mm long, 1.8–3.5(–5) mm wide.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes orange-brown to brown, the lower 3–4 glumes sterile, upper 3–8 glumes frequently bisexual and producing nutlets, (broadly) ovate, 3–4.4 mm long, 2.5–3.8 mm wide, glabrous, keel protruding into an awned apex
Morphology Reproductive morphology Flowers Perianth
Perianth of 6 equal bristles, 3–3.5 mm long
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 2: filaments 2.1–4.5 mm long, becoming stiff and bristle-like in fruit.
Morphology Reproductive morphology Flowers Androecium Stamens Anthers
Anthers ± 1.3 mm long
Morphology Reproductive morphology Flowers Gynoecium Style
Style with 2 long branches
Morphology Reproductive morphology Fruits
Nutlet orange-brown to brown, ellipsoid, the adaxial side flattened, 1.7–3.1 mm long (including the 0.2–0.5 mm long pedicel), 1.2–1.9 mm wide, faintly transversely wavy, with many transparent hairs at its base, crown on top of the nutlet flattened-conical, 0.7–1.2 mm long, whitish.
Ecology
Swampy and boggy grassland; 450–1150 m
Conservation
Least Concern (LC) due to its wide distribution and common habit.
Note
" R. angolensis is closely related to R. brownii, but it is easily distinguished by its glabrous, rounded culms, larger spikelets and longer perianth bristles.
Distribution
Range: Cameroon, Central African Republic, Congo-Kinshasa, Angola, Zambia, Mozambique Flora districts: U4 T1 T8
[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 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.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • 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