Juncus acutiflorus subsp. acutiflorus

Long-rhizomatous perennial. Rhizome stout, (3–)4.5–6 mm diam. Culms erect, 30–110 cm high, laterally compressed near base otherwise terete, 1.5–2.5 mm diam., smooth, hollow, without internal septa, each with 2–4(–6) leaves and 2–3 cataphylls towards the base, mid green, glossy. Leaf-blades slightly flattened, smooth, unitubular, conspicuously transversely septate across whole width, shorter than culms, 10–50 cm long, 1.4–2.5 mm wide, apex acute to acuminate, mid green, glossy; auricles obtuse, to 1–1.5 mm long, scarious. Inflorescence terminal, diffuse, often much-branched, 3–12 cm long; flowers clustered at branch ends, 5–10(–20) per cluster, and (10–)30–80 clusters per inflorescence; primary bract 1, 1.5–10 cm long, usually shorter than or sometimes equalling inflorescence, rarely longer than inflorescence; prophylls absent. Tepals golden brown to red-brown, often paler at base, with ± narrow yellowish margins, the outer shorter than the inner, usually reflexed distally; outer tepals (1.5–)1.7–2.2(–2.5) mm long, acuminate; inner (1.8–)2–2.7; stamens 6, anthers  0.8–1 mm long, longer than the c. 0.3–0.4 filaments. Style 0.8–1 mm long. Capsules golden brown to red brown at maturity, shiny, trigono-ovoid to narrowly pyramidal, c. 2.6–3.5 mm long, gradually tapering to an acute point, longer than the tepals; seeds narrowly ovoid to ellipsoid, 0.4–0.5 mm long, finely reticulate (discernible at high magnification), appendages absent. Flowers Dec.–Jan. (2 records).