Puccinellia rupestris (With.) Fernald & Weath.

Annual or biennial tufts, (6)–10–35 cm, with procumbent to ascending culms and wide leaves; branching intravaginal. Leaf-sheath glabrous, firmly membranous, closely ribbed, light green to creamish brown. Ligule (1.2)–1.5–2 mm, truncate to ± acute centrally. Leaf-blade 2.5–6 cm × 2–5 mm, flat or folded, abaxially finely scabrid on midrib, adaxially scabrid on ribs; margins scabrid, tip hooded. Culm (5)–15–30 cm, overtopping leaves, internodes glabrous. Panicle (2.5)–4–8 × (0.7)–1–5 cm, ovate or oblong, stiff, strongly secund; branches short, scabrid on angles, bearing close-set, very shortly pedicelled spikelets along one side almost to base. Spikelets 4.5–5.5–(7) mm, 3–4-flowered, green. Glumes unequal, strongly nerved, ovate-elliptic, apex minutely scabrid, obtuse, or midnerve sometimes slightly excurrent; lower 1.3–2.2 mm, 3-nerved, upper 2–3 mm, 3–5-nerved. Lemma 2.7–3.5 mm, strongly 5-nerved, with short hairs at base and on lateral nerves near base, elliptic, firm, margin hyaline, apex minutely scabrid, obtuse, or midnerve sometimes very slightly excurrent. Palea = lemma, keels ciliate-scabrid in upper ¾, apex ± entire, shallowly bifid. Rachilla ≥ 1 mm. Anthers 0.8–1.2 mm. Caryopsis 1.6–2 × 0.5–0.7 mm.

[From: Edgar and Connor (2000) Flora of New Zealand. Volume 5 (second printing).]