Flora of New Zealand Series

Type locality: Australian. Type: BM.

Loosely tufted. Stems 9–60 cm. × 2–4 mm., erect, or occ. shortly creeping and rooting at the nodes towards the base, us. compressed, occ. terete. Lvs 8–30 cm. × 2–5 mm., ∞, both basal and cauline, us. < stems, lamina much compressed but hollow, longitudinally multi-tubular, the individual tubes transversely septate, lf-tip us. acute, occ. slightly dilated; sheath broad and loose, with membr. margins and 2 obtuse auricles. Infl. a terminal, much-branched cyme, with globular fascicles of 6–12 fls at the ends of the spreading branchlets; subtending bracts 1–2, lfy, < infl., septate. Fls 3–4 mm. long; tepals acuminate, ± equal or the outer occ. shorter, greenish brown, occ. red, membr. margins very narrow. Stamens 3, c. ½ length of tepals. Capsule 4.5–5 × 1–1.5 mm., us. much > tepals, triquetrous, ovate-lanceolate, gradually narrowed to a mucronate tip, rust- or straw-coloured.

DIST.: N. Throughout. S. Local in Nelson and Westland.

Recorded also from the Philippines, Japan, China, India and Ceylon.

Lowland in swampy ground.

Laing and Wall in T.N.Z.I. 55, 1924, 441 state that J. prismatocarpus was found in a ditch by the side of the road in Kaituna Valley, Banks Peninsula and that it occurs as far south as Peel Forest. No supporting herbarium specimens have been seen, or since collected.