Bromus tectorum L.
downy brome
Annuals, 9-55-(80) cm, loosely tufted or consisting of a solitary culm. Leaf-sheath densely, shortly pubescent, with some longer soft hairs; upper sheaths sometimes ± glabrous. Ligule 0.4-3.5 mm, lacerate. Leaf-blade 1-14 cm × 1.2-5.5 mm, shortly pubescent but with some longer hairs on margins towards base, tip subacute. Culm 6-35-(65) cm, slender, erect, internodes glabrous or minutely hairy. Panicle 3.5-25 cm, lax or contracted, nodding, secund; branches filiform, flexuous, spreading, short-hairy, lowermost bearing 4-8 spikelets. Spikelets 2.2-3.5 cm, 4-8-flowered, lanceolate to later gaping, light green to purple-suffused. Glumes very unequal, lanceolate, acute, membranous, usually pubescent with minute and longer hairs, or rarely glabrous; lower 6.5-9.5 mm, 1-nerved, upper 8.5-12 mm, 3-nerved. Lemma 10-16 mm, 7-nerved, rounded, lanceolate, later wedge-shaped, pubescent or sometimes only slightly scabrid, membranous, with shining hyaline margins tipped by 2 acute lobes, to c. 1 mm; awn 12.5-19 mm. Palea c. ¾ length of lemma, keels ± sparsely ciliate. Callus with extremely minute hairs. Rachilla 2-3 mm, with ± scattered, minute, appressed hairs. Anthers 0.6-0.9 mm. Caryopsis 6-8.5 × 0.9-1.5 mm.
N.: Auckland City (Onehunga); S.: Marlborough, Canterbury, Otago. Waste ground, modified tussock grasslands.
Naturalised from Mediterranean.
Specimens in which the lemmas are finely scabrid rather than pubescent have been collected in North Canterbury near Medbury and Waipara, and also at Bottle Lake, Christchurch.
Although Kirk, T. T.N.Z.I. 3: 148-161 (1871) listed B. tectorum for Auckland, no herbarium specimens were found by Esler, A. E. and Astridge, S. J. N.Z. J. Bot. 25: 523-537 (1987); it was recently collected in Onehunga, Auckland P. J. de Lange 6 Nov 1996 (AK 233145).
