Flora of New Zealand Series

; Holotype: CHR 514885C! G. Jane Flaxbourne River, Marlborough, north side, near mouth, disused limestone quarry, 100 m, 4 Dec 1997.

Robust grey-green tufts, 45-65 cm; branching extravaginal. Leaf-sheath chartaceous with membranous margins, ± distinctly ribbed, glabrous, stramineous, or reddish purple, especially in culm leaves. Ligule 0.7-1.0 mm, truncate, erose, sparsely ciliate, abaxially scabrid. Leaf-blade 6-20 cm × 1.5-3.0 mm, greyish green to later reddish, abaxially smooth, adaxially strongly ribbed, prickle-toothed on ribs; margins finely prickle-toothed. Culm 30-45 cm, nodes green to purple with an upper fringe of dense appressed hairs, internodes glabrous. Panicle 10-16 × 1-1.5 cm, linear-lanceolate, dense, contracted above, longer lower branches in slightly more distant clusters, scarcely spreading, spikelet-bearing to base; rachis, branches, and pedicels with short hair-like prickle-teeth. Spikelets 6-8 mm, green to stramineous or purple-suffused. Glumes 1-nerved, equal or upper very slightly longer, c. 6 mm, submembranous, elliptic-lanceolate, acuminate, keels finely prickle-toothed. Lemma ≤ glumes, 6-7 mm, subcoriaceous, papillose, minutely prickle-toothed above, apex bifid with hyaline finely acuminate lobes 0.5-1 mm; awn 8-12 mm, middorsal, or from slightly above midway, geniculate, twisted, very hairy below. Palea < lemma, folded, keels prickle-toothed above, apex ciliate. Callus c. 0.2 mm, hairs to 4 mm. Rachilla 0.2-0.7 mm, glabrous or with a few hairs; prolongation 0.5 mm. Lodicules c. 0.5 mm, cuneate, ciliate. Stamens 3; anthers 1.0-1.5 mm. Gynoecium: ovary 1-1.3 mm; stigma-styles 0.7-1.5 mm, hairs almost to base. Caryopsis c. 3.5 × 1 mm, beaked; embryo 0.5 mm; hilum 2.0 mm. 2 n = 70 (+ 2f).

S.: Marlborough, near mouth of Flaxbourne River; confined to a disused limestone quarry, 100 m.

Endemic.

In CHR there are two specimens originally collected from the Waima Valley, Marlborough, but grown on at Pinehaven, Hutt Valley; CHR 252333 A. P. Druce tributary of Waima River, Jan 1974, and CHR 387531 A. P. Druce Isolation Creek, Jan 1982. Flowers in both are cleistogamous, and anthers are 0.6-0.9 mm long in florets of smaller dimension than in D. lautumia from Flaxbourne River, c. 20 km to the north-east, where all plants are regarded as chasmogamous. Of the Isolation Creek site A. P. Druce (in litt.) noted that these plants were abundant on the stream bank there. Edgar, E. N.Z. J. Bot. 33: 11 (1995) had included these specimens in her discussion of forms of Deyeuxia quadriseta.