Flora of New Zealand Series

Chilean brome

Soft-leaved, green to bluish green perennial tufts, 3-100-(165) cm, with spreading culms. Leaf-sheath rounded, with dense, fine, soft, horizontally projecting hairs. Ligule 1-1.5 mm, rounded or truncate, shortly denticulate, sometimes with scattered fine hairs at margins or abaxially; in uppermost culm leaves tapered and more lacerate. Leaf-blade 10-20 mm × 3-7 mm, villous; margins finely scabrid, tip subobtuse. Culm usually geniculate at base, usually ascending, to ± erect, internodes glabrous. Panicle 10-20-(35) cm, nodding; branches slender, finely scabrid, lower branches becoming strongly reflexed and drooping, upper branches ascending. Spikelets 2-3.5 cm, 5-7-flowered, linear-lanceolate, usually purple-suffused, sometimes light green. Glumes unequal, acute, with dense, short, soft, straight hairs throughout; lower 6-7.5 mm, 3-5-nerved, narrow-lanceolate, upper 8-9.5 mm, 5-7-nerved, ovate-lanceolate. Lemma 9-12 mm, 7-9-nerved, keeled, densely, shortly hairy throughout, evenly light green to usually purple-suffused; awn 4-6 mm. Palea = or slightly > lemma. Callus with minute hairs. Rachilla scabrid to minutely pubescent. Anthers 0.5-0.8 mm in cleistogamous flowers, c. 3 mm in chasmogamous flowers. Caryopsis 8.1-8.8 × 1.5-1.8 mm.

N.: southwards from Little Barrier Id and Auckland City; S.: Nelson, Marlborough, Canterbury; C. Waste ground.

Naturalised from South America.

Bromus lithobius was earlier equated in N.Z. with North American B. breviaristatus and B. carinatus and latterly with South American B. fonkii, but Forde, M. B. and Edgar, E. ( 1995 op. cit.) followed Matthei, O. Gayana Bot. 43: 47-110 (1986) who concluded that B. fonkii Phil. was a later synonym of B. lithobius.

Bromus lithobius occurs on low fertility lighter, summer dry soils, often on roadsides, but does not survive trampling or drought; two different forms have been collected in Canterbury, one prostrate and one upright with drooping panicles (A. V. Stewart, pers. comm.).