Fuirena coerulescens Steud.

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

South Africa, Cape Province, Cape Flats, xii.1830, Ecklon 868 (B† holotype, K lectotype, M, PRE), lectotypified by Forbes (1997).

Morphology General Habit

Perennial, culms contiguous or to 20 mm apart; rhizome woody and stout, horizontal, 3–9 mm diameter

Morphology Culms

Culms 25–60(80) cm tall, 1–3 mm wide, sharply triangular, glabrous apart from short distance below inflorescence

Morphology Leaves

Leaf sheath glabrous, occasionally puberulous; ligule glabrous or puberulous on upper margin; leaf blade 8–20(31) cm long, 2–5 mm wide, flat or infolded, glabrous, sometimes puberulous adaxially in region of midrib adaxially, ciliate on parts of margin

Morphology Reproductive morphology Inflorescences

Inflorescence a terminal or pseudolateral cluster of up to 12 sessile to shortly stalked spikelets, sometimes with an added cluster, branches puberulous

Morphology Reproductive morphology Inflorescences Bracts

Bracts 2, unequal, erect, puberulous

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 6–15 × 3–4 mm (awns excluded), terete, narrowly ovoid, dark silver-grey

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes 3.5–5 mm long (1–1.5 mm long awn included), puberulous abaxially with a glabrous band (in some collections coloured blue-black) with ciliate edge on distal margin of body, awn subterminal, straight or slightly recurved

Morphology Reproductive morphology Flowers Perianth

Perianth segments 6 in 2 whorls, outer 3 segments of scabrous bristles, as short or longer than nutlet, or absent, inner 3 segments very variable, of scales (with claw and obtriangular blade bearing a scabrid arista) or bristles, or a mixture of these, or reduced or absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3; anthers 1.25 mm (orange-reddish in pressed material)

Morphology Reproductive morphology Fruits

Nutlet pale to dark brown, 1.3–1.6 (including stalk and short conical papillate beak) × 0.7–0.9 mm, dark to pale brown, trigonous, obovoid, substipitate, subhexagonal surface cells arranged in somewhat longitudinal rows may be visible (× 10).

Distribution

Zambia, Zimbabwe. Also in South Africa (Eastern Cape, Free State, Gauteng, KwaZulu-Natal, Limpopo, Mpumulanga, Northern Cape and Western Cape) and Madagascar.

Ecology

In temporary wet situations in seasonal pans and damp grassland where vegetation is sparse; 400– 1500 m.

Conservation

Widespread; not threatened.

Recognition

This polymorphic species is widespread in southern Africa. Fuirena coerulescens can be recognised by the glabrous band, sometimes a different colour, and a ciliate margin to the glume. The rhizome is markedly wide and the culm triangular. The hypogynous whorls in particular show a wide range of variation throughout the distributional range. No evidence was seen of development of either the inner or outer perianth segments in the limited amount of material from Zambia and Zimbabwe. Inner perianth segments resemble those of F. ecklonii Nees but the arista arises from the blade apex.

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