Flora of New Zealand Series

≡Avena quadriseta Labill., Nov. Holl. Pl. 1: 25, t. 32 (1805)

≡Agrostis quadriseta (Labill.) R.Br. Prodr. 171  (1810)

≡Calamagrostis quadriseta (Labill.) Spreng., Syst. Veg. 1: 253 (1824); 

Holotype: FI! Labillardière N. Holl.

Variable, rather slender to robust, dense or lax tufts, 15-125 cm, with culms erect or curved upwards from base, much overtopping leaves; branching extravaginal. Leaf-sheath subcoriaceous, greenish brown, keeled above, distinctly ribbed, smooth or finely scabrid, or ribs rarely short-ciliate. Ligule 1.5-3.5-(6) mm, oblong, truncate, erose or finely ciliate, abaxially glabrous. Leaf-blade 2.5-15-(20) cm × 0.5-3.5-(6) mm, flat or inrolled, abaxially smooth or ribs finely scabrid, adaxially strongly ribbed, margins finely scabrid, tip long-tapered, acute to acuminate, finely scabrid. Culm (10)-15-105 cm, internodes smooth or faintly scabrid. Panicle 3-25-(35) × 0.4-2 cm, narrow-linear, cylindric, or up to 3.5 cm wide and lobed below; rachis smooth to scaberulous, branches finely scabrid, usually ± appressed to rachis or slightly spreading in larger panicles, densely covered with spikelets almost to base, pedicels scabrid. Spikelets (3)-3.5-4-(5) mm, greenish to purplish. Glumes 1-nerved, hyaline, elliptic-lanceolate, acute or acuminate, smooth or sometimes scabrid, midnerve scabrid, margins scaberulous. Lemma 2-3.5-(4) mm, c. ¾ length of glumes, submembranous to firm, smooth and shining below, and finely scabrid near apex, or lightly scabrid to distinctly scabrid-papillose throughout, narrow-lanceolate, apex denticulate with lateral nerves excurrent as 4 minute awns; central awn 1.6-6 mm, geniculate, usually arising from lower ⅓ of lemma, often subbasal, occasionally almost middorsal, ± enclosed within or projecting beyond glumes. Palea ˜ lemma, hyaline, keels faintly scabrid in upper ½. Callus hairs wispy, 0.4-1 mm, c. ⅓ length of lemma. Rachilla prolongation 0, or 0.05-0.3 mm, including hairs if any. Lodicules c. 0.3 mm, linear, obtuse. Anthers 0.3-1.3-(1.8) mm. Caryopsis 1.5-2 × 0.4-0.7 mm.

N.: from North Auckland south to Volcanic Plateau and Taranaki, further south near Wellington; S.: very scattered; St.; Three Kings Is. Lowland form in gumland, scrub, and on roadsides, montane to subalpine form in boggy ground; lowland to subalpine.

Indigenous.

Also indigenous to Australia.

Deyeuxia quadriseta in Australia is very variable and may comprise several distinct taxa [Vickery, J. W. Contrib. N.S.W. Natl Herb. 1: 43-82 (1940)]. For New Zealand Edgar (1995 op. cit. p. 11) distinguished an inland, montane to subalpine form of boggy ground, with narrow, involute leaves, and short, narrow-cylindric panicles with scabrid lemmas bearing awns ± included within the glumes, and a wide-leaved coastal form of disturbed sites, with large ± lobed panicles, long awns, and lemmas which are smooth and shining at the base and only slightly scabrid above. This second form may have been introduced from Australia because it is found in very disjunct localities-gumlands of North Auckland, Taita near Wellington, north-west Nelson, Christchurch, and Bluff.