Glyceria fluitans

Rhizomatous, loosely cespitose, perennial grass.

50–100 cm high.

The culm is typically ascending, glabrous, and the summit of the culm is drooping.

The leaf arrangement is alternate. Leaves are sessile, sheathed and shorter than the culm. The sheath is flat, closed, and smooth. The lamina is moderately broad (4–8 mm), flat and short-acuminate, light green on the adaxial side, and dull on the abaxial side. The ligule is sizeable (5–10 mm).

The inflorescence is a long and narrow (25–50 cm), secund, often slightly drooping panicle. There are typically two branches at the lowest node of the panicle. The shorter one of the branches bears a single spikelet. The longest branch of the middle node of the panicle bears at most four spikelets. The spikelets are long (15–30 mm) and terete, with 7–13 florets. The florets are bisexual. The glumes are hyaline, short and terete, but of different lengths. The outer glume is acute. The lemma is 5–7 mm long, acute, with a broad hyaline margin, and with multiple veins. The anthers are 1.5–3 mm long and often purple.

Grain.