Cortaderia selloana

Plants female or bisexual. Culms to 4.5 m high, nodes glabrous, mostly concealed by leaf-sheaths; leaves glabrous; sheath usually glabrous; blade flat, to 1.8 m long and 2 cm wide, narrowly tapered toward the tips, midrib prominently thickened; ligule a dense row of fine, silky hairs to 4 mm long. Inflorescence a dense, plume-like panicle 25–100 cm long, white, yellowish or purplish. Spikelets 10–17 mm long, spikelets 5–7-flowered; glumes hyaline, narrow-acuminate, 10–15 mm long, subequal; florets narrow-acuminate, about equal to glumes or slightly shorter; lemma narrowly tapered with fine, awn-like apices, 7–13 mm long overall, hyaline, smooth, glabrous or with a few long hairs in bisexual flowers, plumose in female flowers; palea 3–5 mm long, hyaline, glabrous. Flowers Jan–May