Isolepis crassiuscula

Aquatic perennial, with culms leafy, submerged and elongated or creeping and rooting at nodes, or erect and tufted (in non-aquatic situations).  Leaves sheathing, basal one on each branch usually an open sheath, to 10 mm long and to 5 mm wide, upper leaves with sheath closed but tearing readily along the ventral surface, blade linear, 3–12(–18) cm long, 0.5–1.5 mm wide, rather thick. Spikelet solitary, ovate to broad-elliptic in outline, slightly flattened, 12–40-flowered, 5–9 mm long; involucral bract shorter than to slightly exceeding spikelet, glume-like or with short thickened appendage; glumes obtuse, conspicuously numerous-nerved, whitish or straw-coloured, often with orange-brown to dark red-brown dots or patches, 3–4 mm long; stamens 2 or 3; anthers 0.8–1.5 mm long; style 2-fid. Nut plano-convex, with well-defined margins, obovoid to ellipsoid, smooth, minutely reticulate, shining, grey-brown, about half as long as glume, 1.5–2 mm long, 0.8–1.4 mm diam Flowers spring–summer.