General:
Perennial grass from rhizomes with numerous long shoots; stems erect, hollow, (60) 80-200 (250) cm tall.

Leaves:
Sheaths rough; blades 8-18 mm wide, 30-60 cm long, bright green, smooth below, rough above, with 2 pale brown, triangular spots at the base below, the upper leaves indistinctly cross-wrinkled; ligules 2.5-3.5 mm long, blunt at the tips, slightly jagged with a central spine-shaped tip, the tips 1-2 mm long.

Flowers:
Inflorescence a dense panicle, 10-40 cm long, with 4 to 10 branches at the central panicle nodes, the branches relatively thick, nearly erect to spreading, rough, with the main axis rough; spikelets 7- to 9-flowered, egg-shaped, green or tinged with yellow or violet, 2.5-6.5 mm long and up to about 2.5 mm wide; glumes nearly sharp-pointed, the lower ones 2-3 mm long, the upper ones 3-4 mm long; lemmas prominently 7-nerved, blunt, 2.5-4 mm long; paleas blunt, with wide V-shaped notches, 3-4 mm long, concealed by the lemmas; stamens 3; anthers 1-2 mm long.

Source:  The Illustrated Flora of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  The Illustrated Flora of British Columbia

Synonyms and Alternate Names:
Glyceria maxima subsp. grandis (S. Watson) Hultén
Glyceria maxima var. americana (Torr.) B. Boivin
Glyceria spectabilis Mert. & W.D.J. Koch
Molinia maxima Hartm.
Panicularia grandis (S. Watson) Nash