Plants perennial, mat-forming; rhizomes evident, long, 0.5–1.5 mm thick, soft to firm, cortex often breaking loose, longer internodes 5–30 mm, scales often fugaceous, 4–8 mm, membranous, not fibrous. Culms terete, often with 8–12 blunt ridges when dry, firm to soft, internally spongy. Leaves: distal leaf sheaths persistent, not splitting, proximally red, distally green to stramineous, usually inflated, often callose, membranous to papery, apex often red-brown, broadly obtuse to subacute,