Bromus tectorum L.

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.

[From: Edgar and Connor (2000) Flora of New Zealand. Volume 5 (second printing).]