Water couch

Creeping perennials to c. 50 cm tall, with rather slender to rather stout whitish or yellowish rhizomes, and extensive many-noded, branching, stolons often forming loose mats; nodes dark, usually glabrous.

Sheaths pilose on the margins towards the summit, otherwise glabrous; ligule short, 0.5–1.5 mm long, truncate or erose; blade as wide as the top of the sheath, 2–9 mm wide, flat when fresh, often folded and keeled when dry.