Juncus acuminatus Michx.

Strictly erect tufted perennial, commonly reddish-tinged. Stems 30–80 cm high, distinctly septate internally just below inflorescence. Leaves terete or ± compressed with distinct transverse septa. Inflorescence very variable, 3–20 cm long, open, much-branched with 6–10-flowered clusters at ends of branches. Tepals 2.5–3.5 mm long, ± equal, narrow-lanceolate, stiff, acuminate. Stamens 3. Capsules 2.5–3.5 mm long, = or slightly > tepals, narrow, acute, shortly beaked, straw-coloured to brown.

[From: Healy and Edgar (1980) Flora of New Zealand. Volume 3.]