E-Flora BC: Electronic Atlas of the Flora of British Columbia

Ruppia maritima L.
beaked ditch-grass (widgeongrass)
Ruppiaceae (Ditch-grass family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #7513)

E-Flora BC Static Map
Distribution of Ruppia maritima
Click here to view our interactive map and legend
Details about map content are available here
Click on the map dots to view record details.

Species Information

Click on the image below to view an expanded illustration for this species.

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).

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Spring to Summer
Source:  The USDA

Habitat / Range

Tidal marshes and brackish ponds, lakes and ditches in the lowland zone; common along the coast; circumpolar, N to AK, disjunctly E to NF and S to ME, MA, PA, NC, FL, TX, ID and CA; Eurasia, S America.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Ruppia maritima

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 0 128 770
Slope Gradient (%) 0 0 0
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
6 6 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: CDF(4), CWH(2), SBS(1)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

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.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References