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.
S.: Otago, known only from Tomahawk Lagoon and Company Bay, Otago Peninsula. Damp muddy coastal lagoon margin and on harbour-edge road embankment at sea level.
Naturalised from western Europe.
