Perennial, aquatic herb from fibrous roots, rooting at the nodes; stems 30-50 cm long.
Stem leaves threadlike, alternate, 6-12 cm long, 0.2-0.5 mm wide, the tips more or less rounded; stipules membranous, 0.5-2 (7) cm long, fused with the leaves.
Inflorescence on spirally coiled, axillary stalks, the coils 0-3 (4) or lacking, the stalks 3-10 cm long; petals lacking; stamens 2.
Nut-like, egg-shaped, 1.8-2 mm long; beaks terminal, slightly recurved, 0.6-1 mm long.
This is a highly variable species, especially with respect to fruit characteristics. Treatments range from the recognition of only one variable species (including R. occidentalis, e.g., Hitchcock and Cronquist 1973, Dandy 1980) to the recognition of eight or nine varieties (e.g., Scoggan 1978, Brayshaw 1985).
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 from Spring to 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
|CDF(4), CWH(2), SBS(1)|
Source: Klinkenberg 2013
Synonyms and Alternate Names:
Ruppia maritima var. brevirostris J. Agardh
Ruppia maritima var. exigua Fernald & Wiegand
Ruppia maritima var. intermedia (Thed.) Asch. & Graebn.
Ruppia maritima var. longipes Hagstr.
Ruppia maritima var. maritima
Ruppia maritima var. obliqua (Schur) Asch. & Graebn.
Ruppia maritima var. pacifica H. St. John & Fosberg
Ruppia maritima var. rostrata J. Agardh
Ruppia maritima var. subcapitata Fernald & Wiegand
Ruppia pectinata Rydb.