Perennial aquatic herb from a corm-like stem-base and a fibrous root; stems 5-50 cm tall.
All basal, linear, essentially bladeless to long-stalked with narrowly lanceolate blades, from submerged or floating to completely emergent, 3-40 cm long, 0.8-2 cm wide.
Inflorescence an open, bracteate panicle of long-stalked flowers; petals pink or white, slightly longer than the sepals; sepals mostly purple-margined, 2.5-3.5 mm long.
Achenes, 5-20, oblong, about 2 mm wide.
The taxonomy of this species is extremely complex. At present we are recognizing a single taxon. For a discussion of the nomenclatural problems in this species see Reveal (1977).
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
Present over the Summer
Source: The USDA
||Value / Class
Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
of field plots
species was recorded in:
BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in
Source: Klinkenberg 2013
Synonyms and Alternate Names:
Alisma geyeri Torr.
Alisma gramineum var. angustissimum (DC.) A.J. Hendricks
Alisma gramineum var. geyeri (Torr.) Lam.
Alisma gramineum var. gramineum
Alisma gramineum var. graminifolium (Wahlenb.) Hendricks
Alisma gramineum var. wahlenbergii auct. non (Holmb.) Raymond & Kucyniak [misapplied]
Alisma lanceolatum With.
1. Leaf blades broadly lanceolate to egg-shaped; petals usually white.............Alisma triviale
1. Leaf blades linear, lanceolate or narrowly lanceolate; petals pink, pinkish or white.
2. Inflorescence overtopping the leaves; petals 4.5-6.5 mm long, pink or sometimes purplish-pink..............Alisma lanceolatum
2. Inflorescence usually not overtopping the leaves; petals 2.5-3.5 mm long, pink or white.........Alisma gramineum
Source: The Illustrated Flora of British Columbia