Phragmites australis

Semi-aquatic perennial with stout, fleshy rhizomes. Culms leafy, erect, mostly to 3 (rarely to c. 6) m high, sometimes rooting from lower nodes, upper nodes glabrous, but often concealed; leaves glabrous; sheath often remaining on culms after blades have fallen; blade flat or loosely inrolled, to 80 cm long and 4 cm wide, finely scabrous along margins, otherwise smooth; ligule a dense row of silky hairs to c. 1 mm long with scattered longer hairs. Inflorescence a dense ovoid panicle, sometimes interrupted, 10–40 cm long. Spikelets 3–8-flowered, 10–18 mm long; glumes subopposite, subequal, 4–7 mm long; florets narrow-acuminate, of decreasing length from the lowest (sterile) floret to the upper one; lemma pale and membranous at maturity; callus of bisexual florets with a tuft of fine silky hairs about as long as the lemma; palea 3–4 mm long Flowers mainly Nov.–May.