Flora of New Zealand Series

reed sweet grass

Tall, luxuriant, wide-leaved perennial sending up numerous long leafy shoots from a stout creeping rhizome. Leaf-sheath entire at first, later splitting, light green to pale brown, often purplish, paper-like, shining, very finely scabrid to almost smooth, with numerous conspicuous cross-veinlets. Ligule (4)-4.5-6.5 mm, firmly membranous, glabrous, blunt, but tapered centrally to fine point. Leaf-blade (20)-30-50 cm × 10-20 mm, flat, finely striate, very finely scabrid to almost smooth, abaxially scabrid above on conspicuous midrib; margins finely scabrid, tapering abruptly to short ± rigid tip. Culm (5)-10-180 cm, robust, internodes glabrous. Panicle 20-30-(40) cm, lax and open, or contracted and rather dense, broadly ovate to oblong, with numerous spikelets; rachis, branches and pedicels finely scabrid, longer branches naked below. Spikelets (5)-6-7.5-(10) mm, (3)-4-8-flowered, green, or tinged purplish brown. Glumes subequal, hyaline, 1-nerved; lower 1.7-2.5 mm, elliptic-oblong, subacute, upper 2-3.5 mm, ovate-oblong, obtuse. Lemma 2.5-3.5 mm, 7-nerved, elliptic to ovate-elliptic, broadly obtuse, subcoriaceous; nerves minutely prickle-toothed, not reaching upper hyaline minutely prickle-toothed margins. Palea oblong, keels tubercular-scabrid. Rachilla 0.7-1 mm, glabrous. Anthers (1)-1.5-1.8 mm. Caryopsis c. 1.5 × 1 mm.

N.: common in North and South Auckland, scattered further south; S.: Canterbury (near Christchurch, near Hororata), South Otago and Southland, one record from Nelson (Matakitaki R.), and from Westland (Kaniere). An aquatic sp. found in lowland swamps, pools, edges of slow-flowing streams; grows in water to c. 1 m deep.

Naturalised from Europe.