Flora of New Zealand Series

C. polystachya A. Rich. Essai Fl. N.Z. 1832, 118, t. 21 non Swartz ex Wahl. in K. svenska Vet. Akad. Handl. 24, 1803, 149.

Type locality (for C. polystachya): Astrolabe Harbour. Lectotype: P, 2563, D'Urville, 1827; isotypes at P, and at K.

Rhizomatous; robust, 50–150 cm. high, bright green. Culms (1.5)–2–3.5–(5) mm. diam., triquetrous, scabrid on the edges; basal sheaths dull brown or red-brown, margins shredding into fibres wrapped round the culm. Lvs ∞, us. much > culms, 3.5–6–(8) mm. wide, double-folded, margins scabrid. Spikes (6)–10–20, pend. on filiform peduncles, or upper spikes erect, sessile; upper 3–6 spikes male, sometimes mixed with female fls, solitary or the lower geminate, 2–4 mm. diam., glumes hardly awned; remaining spikes female, us. with male fls at the top, geminate, ternate or occ. quinate, lowermost spikes (2)–4–7–(9) cm. × (4)–5–7 mm., upper spikes progressively smaller. Glumes (excluding awn) < utricles, narrow-ovate, obtuse, truncate or emarginate with a hispid awn of variable length, red-brown with a light brown, 3-nerved midrib, margins narrow, hyaline. Utricles (2.6)–3–3.5–(3.8) × (1.3)–1.5–2–(2.3) mm., ovoid to oblong, saccate, inflated or unequally compressed, 6–10-nerved on each face, olive green, becoming greenish brown or red-brown, soft, margins glab.; beak very narrow, c. 0.2 mm. long, orifice entire, rarely slightly bidentate. Stigmas 2. Nut c. 1.5 mm. long, in lower half of utricle, biconvex, orbicular-ovoid or obovoid, brown.

DIST.: N. Throughout except on the eastern side. S. Southwards to lat. 42º, rare further south.

Lowland in peat swamps to 600 m. altitude.

Both Kükenthal (P flanzenr. 38, 1909, 369) and Cheeseman (Man. N.Z. Fl. 1925, 264) referred to C. ternaria (from Auckland Is) all specimens from N., S. and St. in which the infl. was a panicle with basal geminate or ternate spikes. Hamlin (T.R.S.N.Z. 82, 1954, 49–64 and 85, 1958, 394–6) referred these plants to three spp., C. lessoniana, C. geminata and C. coriacea which are chiefly distinguished by the utricle characters given here in the key to spp. However, C. lessoniana also differs from the other two spp. in having a more compact infl. with wider, more erect spikes and in being confined to very damp peat swamps, while C. geminata and C. coriacea are found in a wider variety of habitats.

Occasional plants of C. lessoniana and also of C. geminata bear spikelets which are forked at the tip.