Flora of New Zealand Series

Schoenoplectus lacustris (L.) Palla in Verh. zool. -bot. Ges. Wien  38,  1888,  49.

Type locality: European. Occurs also in Asia, Africa, America, Malesia and Australia.

Rhizome 3–8 mm. diam., hard and woody, red-brown, with loose, papery, grey, rather distant scales, c. 2 cm. long; roots very ∞, fibrous, reddish. Culms (60)–100–160–(270) cm. × 3–5–(8) mm., crowded or distant on the rhizome, terete, with spongy pith. Lvs reduced to loose, grey-brown, papery sheaths at base of culms, the uppermost to 35 cm. long. Infl. apparently lateral, of ∞ spikelets in a cymose irregular umbel, primary rays 1–6 cm. long, scabrid; subtending terete bract much < infl. Spikelets 6–11 mm. long, oblong-ovoid or oblong-ellipsoid, light brown, solitary, or in clusters of 2–4 on long, scabrid peduncles. Glumes smooth, ovate, emarginate with an awn in the notch, c. = mature nut in length; margin narrow, hyaline, fringed. Hypog. bristles 5–6, ± = nut, retrorsely scabrid. Stigmas 2, very rarely 3. Nut 2–2.5 × c. 1.5 mm., obovoid, plano-convex, apiculate, smooth, light grey.

DIST.: N. Throughout. S. Nelson, Marlborough and Westland, elsewhere only at Christchurch and Lake Ellesmere.

In brackish, fresh, and hot-water swamps, and on the margins of rivers, lakes and ponds; sea level to c. 300 m. altitude.

FL. 11–1. FT. 1–5.

The above description is based on N.Z. plants. These, together with plants of N. and S. America and Asia, have often been considered distinct from European S. lacustris sens. strict. under the name S. validus Vahl. Koyama has also identified N.Z. specimens as S. lacustris L. subsp. creber (Vahl) Koyama var. luxurians (Miq.) Koyama in Phytologia 8, 1963, 458; see also Can. J. Bot. 40, 1962, 927.