Semi-erect to procumbent herb; rhizomatous, with aerial rooting and branching; stem not more than 35 cm long, branching 2–7.5 cm above the ground, forming with the leaves clumps 60–80 cm high; aerial branches spreading or ascending, 7.5–25 cm long, 2–3.5 cm in diameter, rooting, covered on the lower part with very acute spine-tipped white-edged green scaly leaves 1.9–3.8 cm long, 4.5 cm wide, which gradually pass into the leaves. Leaves irregularly directed, sometimes ± distichous, both arrangements occasionally occuring on the same stem, ascending or spreading, (5–)7–18(–23) per plant, cylindric, 15–60≈1.3–1.9 cm, rough throughout but smooth at the basal part and rough above, sheathing at the base and usually with a concave channel extending from sheath 1–2 cm way up the leaf, apical spine 0.3–0.6 cm long, gradually tapering to a very acute horny ending, brownish grey; dark green, faintly banded with pale green and marked with darker green in full sun but less marked in deep shade; abaxial surface continuous and interrupted with longitudinal lines, which with age or on shrivelled leaves become impressed, forming furrows. Inflorescence a spike-like green raceme, 30–38 cm long, axis 0.4–0.6 cm wide, thickly covered with minute whitish linear dots; flowers 2–5 per cluster; lower inflorescence bracts 2–4, membranous near base, 4.4–6.9 cm long on the upper inflorescence, acute; bracteoles ovate, 0.1–0.4 cm long, acute or acuminate, membranous; pedicels 0.3–0.4 cm long, jointed at or above the middle. Flowers whitish grey to greenish white at apices with reddish brown to dark brown outside; tube 1–2 cm long, slightly enlarged at the base, lobes (0.9–)1.2–1.4 cm long, recurved-spreading or with reflexed tips; anthers 2.5 cm long.
