Cyperus dubius Rottb.

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

Type

Type: India, König s.n. (C, holo.; photo!)

Morphology General Habit

Perennial with tufted culms up to 45 cm tall, with a bulbous culm-base.

Morphology Culms

Culms many, crowded, sometimes semi-succulent, 8–40 cm long, 0.5–2 mm wide, bluntly to sharply triangular, glabrous.

Morphology Roots

Roots fragrant (fide Hooper 928)

Morphology Leaves

Leaves many, up to 33 cm long, often recurved. Leaf blade bright green or glaucous in very dry situations, linear, flat or slightly v-shaped, 5–33 cm tall, 1–4(–5) mm wide, scabrid on at least margin and primary vein, apex attenuate Leaf sheath pale brown, thin and membranous, the lower somewhat thicker, brown and occasionally splitting up into fibres, to 4 cm long.

Morphology Reproductive morphology Inflorescences Bracts

Involucral bracts leaf-like, erect to spreading, 3–6, lowermost 4–23 cm long, 0.5–3.5 mm wide

Morphology Reproductive morphology Inflorescences

Inflorescence capitate, green or greenish white or white tinged green, hemispherical to ovoid, 5–15 mm in diameter, of 3–6 congested sessile spikes.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets narrowly ovoid, 2–6 mm long, 1–2 mm wide, 3–9(–18)-flowered but with only few maturing nutlets.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes greenish with uncoloured margin, ovate, 2–3 mm long, keel narrow, with 5–8 slender veins on either side, apex concave

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2–3, with white filaments and yellow anthers.

Morphology Reproductive morphology Flowers Gynoecium Style

Style white

Morphology Reproductive morphology Fruits

Nutlet brown with dark brown angles, obovoid, trigonous, 1.2–1.4 mm long, (including 0.1–0.2 mm long apiculus), 0.8–0.9 mm wide, strongly papillose.

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

India, König s.n. (C holotype).

Morphology General Habit

Perennial, perhaps sometimes annual, with bulbous-based tufted culms up to 45 cm tall, the base covered in translucent brown scales, without rhizomes; culms many, crowded, sometimes semi-succulent, 8–40 cm long, 0.5–2 mm wide, bluntly to sharply triangular, glabrous

Morphology Leaves

Leaves many, up to 33 cm long, often recurved; leaf sheath pale brown, thin and membranous, the lower somewhat thicker, brown, to 4 cm long; leaf blade bright green or glaucous in very dry situations, linear, flat or slightly v-shaped, 5–33 cm long, 1–4(5) mm wide, scabrid on at least margin and primary vein, apex attenuate Leaves 1–5 mm wide. Head 5–15 mm in diameter; glumes 2–3 mm long

Morphology Reproductive morphology Inflorescences Bracts

Involucral bracts leaf-like, erect to spreading, 3–6, lowermost 4–23 cm long, 0.5–3.5 mm wide

Morphology Reproductive morphology Inflorescences

Inflorescence capitate, green to almost white, hemispherical to ovoid, 5–15 mm in diameter, often of a single spike but sometimes of 3–6 congested spikes and then appearing lobed; spikelets narrowly ovoid, 2–6 mm long, 1–2 mm wide, 3–9(18)-flowered but with only few maturing nutlets; glumes greenish with uncoloured margin, ovate, 2–3 mm long, keel narrow, with 5–8 slender veins on either side, apex concave

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2–3, with white filaments and yellow anthers; style white

Morphology Reproductive morphology Fruits

Nutlet black to brown with dark brown angles, obovoid, trigonous, 1.2–1.4 mm long, (including 0.1–0.2 mm long apiculus), 0.8–0.9 mm wide, papillose Nutlets 1.2–1.4 mm long.

Distribution

Botswana, Zambia, Zimbabwe, Malawi, Mozambique. Widespread in the drier parts of tropical Africa; also in India.

Ecology

In various types of woodland, bushland or grassland, often in shallow soil over rock outcrops; occasionally ruderal; 0–1600 m.

Conservation

Least Concern because of its wide distribution.

Note

F.T.E.A. notes that the roots are fragrant but this probably refers to the bulbous stem-base.

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/177111/17771273

Conservation

LC - least concern

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