Flora of New Zealand Series

marram grass

Long-rhizomatous, wiry-leaved perennials forming compact, glaucous-grey tufts to 170 cm; with strong woody rhizomes and numerous fibrous roots; branching intravaginal. Leaf-sheath glabrous, light straw-brown or brownish purple. Ligule 15-30 mm, membranous, narrowed to a point, abaxially covered with very minute hairs. Leaf-blade 35-60 cm × c. 1.5 mm diam., tightly involute, abaxially glabrous, adaxially ribbed, ribs densely short stiff hairy. Culm 70-145 cm, internodes usually scabrid, sometimes smooth to slightly scabrid. Panicle 15-25-(35.5) cm, spike-like, cylindric, tapering above, with numerous crowded light green spikelets; rachis minutely scabrid, erect branches and pedicels hidden among spikelets. Glumes 9.5-14 mm, ± equal, persistent, subhyaline, narrow-lanceolate, glabrous, keel and margins minutely scabrid, tip blunt or obtuse; lower usually 1-nerved, upper usually 3-nerved. Lemma 8.5-13 mm, < glumes, 5-nerved, narrow-lanceolate, obtuse, minutely apiculate, keeled, keel minutely scabrid. Palea 2-4-nerved, subhyaline, central nerves minutely scabrid. Lodicules 1.5-2.5 mm. Callus ringed by long straight silky hairs. Rachilla prolongation bearing long, straight, silky hairs. Anthers 3.5-5.5 mm. Caryopsis c. 3 mm.

N.; S.: throughout; St.; Ch. Coastal sand dunes and occasionally inland - in Volcanic Plateau and at Erewhon Park in Rangitata Valley.

Naturalised from Europe.

Ammophila arenaria is an effective binder of drifting sand and has become naturalised in most temperate countries. In N.Z. marram grass is much planted to stabilise sand dunes where it spreads rapidly vegetatively and occasionally from seed. In many areas it has replaced the native Spinifex sericeus and the golden sand-sedge or pingao, Desmoschoenus spiralis.