Flora of New Zealand Series

≡Asprella laevis Petrie, T.N.Z.I. 27: 406 (1895)

≡Cockaynea laevis (Petrie) Zotov, T.R.S.N.Z. 73: 234 (1943) comb. illeg.

≡Hystrix laevis (Petrie) Allan, N.Z. DSIR Bull. 49: 88 (1936)

≡Elymus laevis (Petrie) Á.Löve et Connor, N.Z. J. Bot. 20: 184 (1982) non Hoover (1966); 

Lectotype: WELT 68353! D. Petrie Matukituki Valley, 3/1893 (designated by Connor 1994 op. cit. p. 147).

Perennial grass with long stolons, rooting and shooting at nodes, inflorescences narrow and nodding or drooping on long slender culms. A species of grasslands. Leaf-sheath 5-10 cm, with retrorse hairs 0.5 mm, or glabrous; keeled. Auricles absent or minute, 0.15-0.25 mm, scarcely clasping. Ligule 0.5-1 mm, lacerate; prominent. Leaf-blade 15-25 cm × 1.5-2 mm, flat, thin, abaxially with distinct midrib, glabrous or occasionally with hairs 1 mm beside ribs or shortly retrorse prickle-toothed, adaxially with prickle-teeth on ribs occasionally with hairs 0.5 mm; margin glabrous or shortly toothed. Culm 50-75 cm, nodes inconspicuous, internodes glabrous, slender. Inflorescence very narrow, slender, 8-15 cm, of 10-25 spikelets > internodes; internodes 2.5 mm to 6 mm below; rachis prolongation 3-6 mm. Spikelets 8-12 mm, of 1-2 florets, appearing shortly stipitate above glumes; rachilla prolongation 3-4 mm, shortly prickle-toothed. Glumes 2, awnlike, 2-6 mm, ± equal, > internodes, 1-nerved, prickle-toothed on keel and margins, < spikelet. Lemma 6.5-8 mm, smooth except for prickle-teeth towards bifid apex and evident on lateral nerves in upper half; keel ± prominent; scabrid awn 0.5-1 mm. Palea 6.5-7 mm, ≤ lemma; apex bifid; keels shortly toothed and inrolled. Callus 0.5-0.75 mm, flat; disarticulation almost flat. Rachilla to 1.3 mm if 2-flowered, shortly prickle-toothed. Lodicules 0.75-1.75 mm, lobed or entire. Anthers 1.6-2.6 mm, often retained on apex of caryopsis. Gynoecium: ovary 1-2 mm; stigma-styles 1.75-2.25 mm. Caryopsis 4 mm; embryo 1-1.3 mm. Chasmogamous and cleistogamous. 2 n = 28.

N.: north-west Ruahine Range (Reparoa Bog); S.: throughout except Nelson, Buller and Westland; St. Grasslands, often in flushed sites; sea level to 1300 m.

Endemic.

HYBRIDISM

For natural intergeneric hybrids with Elymus see Elymus. Experimental interspecific and intergeneric hybrids are treated in Löve and Connor (1982 op. cit.). Although genomic formulae are allocated there they lack the precision of modern genomic interpretation.

Connor, H. E. N.Z. J. Sci. Tech. 38A: 742-751 (1957) showed that S. gracilis is self-compatible.