Caespitose perennial, 5-35 cm, stem base bulbous, with tillers. Stem 0.5-1 mm diam., trigonous, smooth. Leaves c. half of stem length; sheaths to 60 mm, grey, strongly veined, blackish and with age disintegrating into fibres, mouth margin concave; blades up to 20 cm, 2.5 mm wide, flat, greyish green, margins smooth or margins and midnerve below towards apex scabrous, apex long-attenuate, acute, trigonous, scabrous. Inflorescence by 1 - 6, commonly 3, sessile, compact, globose, greenish-white heads (clusters of spikes), 6-10 mm, central head usually larger and longer than others; cluster of spikes of 50-100 spikes, spirally arranged; 2-4 bracts foliose, to 10 cm, spreading or reflexed; spikes 2-2.5 x c. 0.8 mm, ovoid, with minute pedicel; scarious, glume-like bract c. 1 mm; glumes 2, opposite, keeled and folded, acute, keel smooth, prominent, sides scarious with 3 prominent yellow-brown nerves. Stamens 2. Nut c. 1.2 mm, ovoid, compressed, brown, papillose.
Rhizomatous perennial; rhizome short. Culms densely tufted, 5–17(–35) cm by 0.5–1 mm, trigonous, smooth, base swollen. Leaves: blade narrowly linear, 3–28 cm by 1–3 mm, acuminate, flattish-plicate; sheath 1–4 cm long, pale to mid-brown. Involucral bracts 3–4, the longest up to 10 cm long. Inflorescence capitate, 0.8–1 by 0.8–0.9 cm. Spikes (1–)3(–5), central spike globose or ovoid-globose, 0.5–0.8 by 0.5 cm, lateral spikes globose, smaller. Spikelets oblong or oblong-lanceolate, 1.7–2 by 0.6 mm, 1-flowered. Glumes usually 4, oblong-ovate to oblong-lanceolate, 0.5–2 mm long, acute, sides hyaline, pale greenish, 1–7-nerved, keel smooth. Stamens 2; anthers 0.9–1 cm long. Nutlets 1 per spikelet, oblong, 1–1.3 by 0.5 mm, maturing brownish.
Tropical Africa, through India (type) to Thailand, Indo-China and S. China. Possibly introduced in Singapore and Australia.
| Name | Language | Country | |
|---|---|---|---|
| sampi bo haeng (สามปีบ่อแห้ง)(Eastern) | Thai | THA |
|
