Flora of New Zealand Series

; Holotype: CHR 133878! V. D. Zotov Old Man Range, Otago, water-course, 5200', 13.2.1963.

Small, stoloniferous, almost completely glabrous, brownish green perennial tufts, c. 5-15-(25) cm, culms overtopping leaves; branching extravaginal; leaf-blades persistent. Leaf-sheath membranous, glabrous, ribbed, keeled. Ligule 0.5-1.5 mm, entire, tapered, glabrous throughout. Leaf-blade 1-3.5 cm × 1-2 mm, flat or folded, subcoriaceous, smooth, but midrib scabrid near curved tip; margins finely scabrid. Culm 3-15-(20) cm, very slender, erect or geniculate at base, internodes glabrous. Panicle 1-3 cm, ± open or contracted, with few, ovate spikelets; rachis, branches and pedicels slender with sparse, scattered prickle-teeth. Spikelets 2-3-(3.5) mm, 2-3-flowered, light green, tinged purple. Glumes unequal, submembranous with hyaline margins, a few prickle-teeth on midnerve near tip; lower 1.5-2 mm, 1-nerved, narrow-lanceolate, acute, upper 2-2.5 mm, (1)-3-nerved, elliptic-oblong, subobtuse to obtuse. Lemma 2-2.5 mm, 5-nerved, elliptic-ovate, obtuse, glabrous, but midnerve with short crinkled hairs to c. ½ length and sparsely prickle-toothed near tip, lateral nerves with a few hairs near base. Palea 1.5-1.8 mm, keels minutely scabrid, interkeel glabrous. Callus with a few wispy hairs. Rachilla c. 0.5 mm, glabrous. Lodicules c. 0.1 mm. Anthers 0.3-0.4 mm. Gynoecium: ovary 0.4-0.5 mm; stigma-styles 0.8-1 mm. Caryopsis c. 1 × 0.5 mm.

S.: mountains of Central and western Otago, and Eyre Mts, Southland. Alpine in damp ground.

Endemic.

Known only from the Old Man and Pisa Ranges until late 1980s when A. P. Druce collected it from Mt Cardrona in the Crown Range, Treble Cone in the Harris Mts, Old Woman Range, and Jane Peak in the Eyre Mts. In most of these specimens the culms are taller than in those specimens on which the original description was based.

Poa senex is one of three low-growing, small-anthered, alpine spp. found in damp situations; it differs from both P. sublimis and P. incrassata in having hairs on the lemma nerves; from P. sublimis it is also distinguished by the more contracted panicle with firmer branchlets, and from P. incrassata by the wider leaves, and by the flat, not hooded, lemma tip and glabrous, not papillose, lemma internerves.