Phalaris arundinacea

Rhizomatous perennial, culms stout, erect, to 200 cm high. Leaves smooth and glabrous; blade 10–35 cm long and 6–18 mm wide; ligule obtuse, membranous, soon becoming torn, 2.5–16 mm long. Panicle with spreading branches at anthesis (rarely quite cylindric), 5–25 cm long and 1–5 cm wide. Spikelets crowded, 4–6 mm long; glumes 3–5-nerved, subequal, lanceolate, acutely keeled; sterile lemmas subequal, linear, 1–1.5 mm long, long-hairy; fertile lemma broad-lanceolate, 2.5–4 mm long, with a few hairs toward apex. Flowers Nov.–Jan.