Sorghum halepense (L.) Pers.

Robust perennials to 2 m, strongly rhizomatous with far-creeping, woody rhizome c. 0.5–10 mm diam., rooting at nodes, internodes covered by scale-like bracts. Leaf-sheath chartaceous, ± keeled above with strong midrib, glabrous, light green or straw-coloured, often streaked reddish purple, sometimes completely suffused red-purple near base. Ligule 3.5–5 mm. Leaf-blade to 90 × 1–2–(5) cm, linear, ± glabrous, adaxially densely pubescent near ligule, abaxially pubescent from margin, midrib prominent, pale cream; margins minutely scabrid. Culm simple, erect, internodes glabrous, often with red-purple streaks. Panicle large, rather open, (15)–20–30 cm, lower branches very long, narrowly ascending, sometimes ± pendulous, naked below. Racemes several towards ends of slender branches; rachis and pedicels finely short-hairy. Pedicelled spikelets: 5–7 mm, greenish or dark reddish, narrow elliptic-lanceolate, acute; anthers c. 3 mm. Sessile spikelets: glumes 4–5 mm, elliptic-lanceolate, almost glabrous to densely hairy; lemmas < glumes, hyaline, sparsely hairy, lemma of upper floret usually awned, awn geniculate, twisted, 10–15 mm; stamens 3, anthers 2–3 mm; caryopsis c. 3 × 1.5 mm.

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