Flora of New Zealand Series

barb grass

Small annual tufts 10-30-(45) cm, often growing closely together to form large patches, plants usually rigidly erect but sometimes with shoots appressed to ground. Leaf-sheath submembranous, glabrous, straw-coloured, striate. Ligule 0.2-0.7 mm, membranous, glabrous, truncate, erose, projecting slightly upwards on either edge. Leaf-blade 2.5-9-(11.5) cm × 1.2-1.7 mm, flat, or inrolled and c. 0.5 mm diam., abaxially glabrous, adaxially ribbed, ribs minutely scabrid. Culm 5-30 cm, sometimes purplish, usually branched near base, internodes glabrous. Inflorescence a single simple spike, breaking up at maturity by disarticulation of rachis below each spikelet. Spikes 6.5-15 cm, cylindric, rather thick, straight or slightly curved, light green; rachis internodes ≤ spikelets, hollowed on one side. Spikelets 5-7.5 cm, 1-flowered, sessile, solitary, edgewise to rachis, alternating on opposite sides of rachis, ± sunk in cavities within it; each floret ± concealed by one glume, uppermost floret with 2 glumes. Glumes 9-nerved, very hard, thick and rigid, oblong-subulate, acute, outer nerves slightly scabrid near apex; glume concealing floret at first, but later sometimes recurved and projecting stiffly at 45 from the rachis. Lemma 4.5-6.2 mm, with back appressed to rachis, membranous, finely 3-nerved with lateral nerves indistinct, lanceolate, acute, glabrous. Palea ≈ lemma, 4-5.5 mm, hyaline, glabrous, keels 2, indistinct. Lodicules 2, glabrous, 1-1.5 mm. Stamens 3; anthers 1.5-2.5 mm. Caryopsis c. 3-3.5 × 0.8-1.1 mm, longitudinally grooved; embryo small; hilum short, linear to oblong.

N.: Auckland City, near Kawhia, Tauranga; S.: North Canterbury (Saltwater Creek), near Banks Peninsula (head of Lyttelton Harbour, Kaituna near Lake Ellesmere, Kaitorete Spit). On salt flats.

Naturalised.

Indigenous to western Europe, the Mediterranean and western Asia and now naturalised in temperate regions of both Hemispheres; formerly known as Lepturus cylindricus and Monerma cylindrica.