Eleusine tristachya (Lam.) Lam.

Tufted perennials, 14–20 cm, sometimes shortly rhizomatous; branching intravaginal. Leaf-sheath light green to pale creamy brown, glabrous, rounded at base and keeled above, coriaceous; margins wide, hyaline. Ligule 0.3–0.5 mm, truncate, ciliate. Leaf-blade 4–8 cm × 2–3 mm, coriaceous, folded, glabrous; margins scabrid and sometimes with a few, scattered long, very fine hairs, midrib scabrid near obtuse tip. Culm 9–18 cm, compressed, internodes glabrous. Inflorescence of 2 oblong, digitate spikes, occasionally a third slightly distant spike; spikes 1–2 × (0.5)–0.8–1.2 cm; rachis long-hairy at base, glabrous above but with 1 or 2 long hairs at base of some spikelets. Spikelets 5–6.5 mm, 4–10-flowered, usually purplish. Glumes unequal, < spikelet, membranous, subacute, keel stiffly scabrid, narrowly winged; lower 1.5–2 mm, 1–3-nerved, upper 2–3 mm, 5–(7)-nerved. Lemma 3.5–4 mm, membranous, subacute, 3-nerved, keel thickened, scabrid, with 2–3 subsidiary nerves near margin above, each marginal nerve with a short, close, subsidiary vein. Palea 2.5–3 mm, keels scabrid, hardly winged, apex ciliate, acute or bilobed. Lodicules 0.6–0.9 mm, nerved, asymmetrically 3-lobed. Anthers 0.6–0.8 mm. Caryopsis c. 1 × 0.8 mm, ± oblong, truncate, red-brown to almost black, with parallel ± transverse ridges, concave on hilar face; hilum small, basal, round.

[From: Edgar and Connor (2000) Flora of New Zealand. Volume 5 (second printing).]