Annual herb, usually densely tufted. Stems simple or branched, erect, jointed, 2-angled, 5–20 cm high, c. 1 mm wide. Leaves linear, 2–6 cm long, 1–2 mm wide. Rhipidia 3–7-flowered. Spathes opposite, lanceolate with abruptly contracted apices; outer spathe 1.8–3 cm long, inner 1.5–2.3 cm long; margins scarious, white. Perianth urceolate below, spreading above, 5–7 mm diam., pale yellow with brown-purple markings in centre; lobes oblong-acuminate, puberulous outside. Stamens exceeding style branches; filaments 1–1.5 mm long, two-thirds connate, dilated and papillose at base; anthers to 1 mm long. Ovary c. 1 mm diam., puberulous. Capsule globose, 2–3 mm diam., glabrous, green to reddish. Seeds globose, c. 0.7 mm diam., rugose, black.