Koeleria riguorum
A. P. Druce nr Lonely L[ake], Douglas Ra., N.W. Nelson, 1400 m, seepage in tussock land, Feb 1984.
Slender, low-growing, to 25-(36) cm, with fine rhizomes, leaves often reddish purple, diverging at an angle of c. 30 , and erect panicles at maturity well overtopping leaves; branching extravaginal, often intravaginal above; sheaths persistent and becoming dark brown. Leaf-sheath strongly ribbed, abaxially puberulous between ribs, pale straw to purple-suffused. Ligule 0.6-1.1 mm, truncate to subacute, ciliate. Leaf-blade 3.2-9.5-(17) cm × 0.3-1.2 mm, usually folded or involute, or flat, linear to filiform, abaxially glabrous, very rarely pubescent, adaxially strongly ribbed, ribs puberulous; margin finely scabrid. Culm 5.8-20-(30) cm, often geniculate at base, erect, stramineous to reddish purple, internodes glabrous, or rarely pubescent or villous. Panicle 2-5-(7) × 0.3-1.0 cm, spike-like, ± interrupted; rachis, branches, and pedicels pubescent, rarely glabrous. Spikelets (3.6)-4.2-6.5 mm, 2-(3)-flowered, bright green, noticeably banded with purple and golden brown, later stramineous. Glumes subequal, lanceolate to elliptic-ovate, acute or obtuse, margin often minutely toothed above; lower 3.5-4.1 mm, 1-3-nerved, narrower than upper, keel scabrid in upper ⅓, upper 4.0-4.2 mm, 3-5-(7)-nerved. Lemma 4.0-4.6 mm, elliptic, often minutely scabrid above, entire or mucronate or shortly apically awned or with a short, slender, straight, subapical awn to 2 mm, apex entire or minutely bidentate. Palea 4.0-4.2 mm, keels prickle-toothed above; palea of lower floret < lemma, palea of upper floret = lemma. Callus hairs 0.2-0.4 mm. Rachilla 0.8-1.2 mm, hairs to 0.9 mm; prolongation to 1.5 mm, hairs to 1.0 mm. Lodicules (0.5)-1.0-1.2 mm. Anthers (0.5)-0.9-1.7 mm. Gynoecium: ovary 0.8-1 mm; stigma-styles c. 1 mm. Caryopsis c. 2.0 × 0.7 mm.
S.: north-west Nelson, St Arnaud Ra., Spenser Mts. Wet areas in tussock grassland; 1480-1670 m.
Endemic.
In its lax habit and narrow interrupted panicles K. riguorum resembles some forms of K. novozelandica but differs from that species in the longer more slender rhizomes, leaf-blades diverging at an angle of c. 30 rather than ± erect, reddish leaves and culms, the conspicuously purplish and golden-brown colour banding in the spikelets, and the longer palea, relative to the lemma, in the second floret.
A preference for damp habitats is unusual in Koeleria but Moore, D. M. Fl. Tierra del Fuego 299 (1983) reported the habitat of K. fueguina Calderón as moist grassland and bogs.
