Cyperus macrostachyos Lam.

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/177048/120159483

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

Cyperaceae, Miss S. S. Hooper. Flora of West Tropical Africa 3:2. 1972

Morphology General Habit

Rather robust annual

Morphology Leaves

Few, flaccid leaves

Morphology Reproductive morphology Inflorescences

A conspicuous spreading inflorescence

Ecology

In or near open water and other damp places.

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

Type

Type: Africa, ‘ExAfrica’ Herb. Lamarck (P-LA, holo.)

Morphology General Habit

Robust annual, up to 100 cm high.

Morphology Culms

Culms solitary or tufted, 26–82 cm long, 1.6–6.2 mm wide, trigonous, sometimes almost triquetrous, smooth, the lower part covered by broad membranous reddish-brown leaf bases

Morphology Leaves

Leaf sheath pale brown to dark brown, 2–13 cm long, the base often reddish-purple. Leaf blade linear, 15–50 cm long, 2.6–9 mm wide, acuminate, apex scabrid Leaves up to 60 cm long.

Morphology Reproductive morphology Inflorescences Bracts

Involucral bracts spreading. Leaf-like, 3–5, 12.5–58 cm long, 2.4–12 mm wide, scabrid

Morphology Reproductive morphology Inflorescences

Inflorescence simple, or sometimes ± compound.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets in clusters on elongated axis at the end of primary branches, at least one cluster sessile, primary branches 2–8, 1–15.5 cm long, at the base with a conspicuous tubular, (pale) red-brown prophyll. Spikelets 10–30 up to many per cluster, linear-lanceolate, 8.7–25 mm long, sometimes elongating up to 35 mm long in fruit, 1.7–2.5 mm wide, the glumes spreading in fruit, then up to 3 mm wide.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes (golden-)yellow, (golden-) brown to reddish brown, with a distinct white hyaline margin, obovate, 2–2.8 mm long, 1.1–2 mm wide, keel rounded to acute, 2–3-veined, pale green, apex obtuse to sometimes ± acute

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens (2–)3.

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Filaments 1.8–2.6 mm long.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers 0.4–0.9 mm long

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma 2-branched

Morphology Reproductive morphology Fruits

Nutlet greyish-black, brownish-black to black, oblong to obovoid, flattened, 1.5–1.9 mm long, 0.6–1.3 mm wide, with minute papillae in longitudinal rows.

Ecology

In seasonal lakes and ponds, at river edges, sometimes in rice fields; sea-level up to 1400 m

Conservation

Least concern (LC) due to its wide distribution

Note

This species is the most robust annual in the Flora area, easy recognized by the white hyaline glume margin.

Distribution

Range: Widespread in Africa; Madagascar, (sub)tropical America Flora districts: U1 U2 U3 U4 K3 K4 K7 T1 T2 T4 T5 T6 T7 T8 Z

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

‘Ex Africa’, Herb. Lamarck s.n. (P-LA holotype). FIGURE 14.47.

Morphology General Habit

A usually robust annual or short-lived perennial; culms usually solitary but sometimes 2–3(4), erect, to 1.25 m long and (1)1.5–6 mm wide, triangular, smooth, lower part covered by broad membranaceous leaf sheaths

Morphology Leaves

Leaves basal, sheaths to 20(30) cm long, pale brown to reddish; blade flat, to 50 cm long and 2–8 mm wide, scabrid near tip

Morphology Reproductive morphology Inflorescences

Inflorescence a solitary or compound umbel-like anthela, 5–25 cm long, each of one to several sessile and 2–10 stalked elongated primary racemose clusters, these again often with sessile and stalked clusters, each cluster with 15–30 loosely arranged spikelets; peduncles of stalked clusters 1–16 cm long; involucral bracts leaf-like, 2–5, largest (10)15–45 cm long and (1)2–6(10) mm wide, scabrid near tip or along whole length

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 7–25 × 1.5–3 mm (to 35 mm in fruit), linear-lanceolate; rachis becoming slightly zig-zag in fruiting stage; glumes appressed at first, spreading from flowering stage, falling at maturity, yellowish to golden brown or dark brown, obovate with a distinct white hyaline margin, narrowing in basal part, 1.5–3(3.5) × 1–2 mm, obtuse to acute, keel green

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens (2)3; filaments 2–2.5 mm long; anthers 0.5 mm long

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma branches 2, 1–2 mm long

Morphology Reproductive morphology Fruits

Nutlet oblong to obovoid with very slightly tapering apex, shortly apiculate, greyish black to black, 1.5–2 mm long, with numerous minute papillae in longitudinal rows.

Distribution

Botswana, Zambia, Zimbabwe, Malawi, Mozambique. Widespread in tropical and South Africa; also in Madagascar and tropical America.

Ecology

Wet and swampy grassland around lakes and waterholes, waterholes in woodland, riverbanks, often in water; 300–1450 m.

Conservation

Widespread distribution; Least Concern. In common and widespread habitats.