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

Ruppia cirrhosa (Petagna) Grande
spiral ditch-grass (spiral ditchgrass)
Ruppiaceae (Ditch-grass family)

Introduction to Vascular Plants

© Curtis Bjork  Email the photographer   (Photo ID #15783)

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Distribution of Ruppia cirrhosa
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Species Information

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Perennial, aquatic herb from fibrous roots, rooting at the nodes; stems 30-80 cm long.
Stem leaves threadlike, alternate, 3-40 cm long, 0.2-0.5 mm wide, the tips sharp-pointed; stipules membranous, 0.5-2 (7) cm long, fused with the leaves.
Inflorescence on spirally coiled, axillary stalks, the coils 5 to 30, the stalks 0.2-2.5 cm long; petals lacking; stamens 2.
Nut-like, egg-shaped, 1.5-2 mm long; beaks lateral, erect, 0.5-1 mm long.
This treatment follows that of Thorne (1993) and Haynes (2000) although there is still some doubt as to whether North American R. cirrhosa is the same as the European.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Ponds, lakes and ditches in the lowland, steppe and montane zones; infrequent along the coast, frequent in SC BC and rare in SE BC; circumpolar, N to AK, YT and NT, E to MB and S to OH, IL, TX, NM, AZ and CA; Europe, S America.

Source: The Illustrated Flora of British Columbia


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 cirrhosa subsp. occidentalis (S. Wats.) A.& D. L÷ve
Ruppia maritima var. occidentalis (S. Watson) Graebn.
Ruppia maritima var. spiralis (Dumort.) Moris
Ruppia occidentalis S. Watson
Ruppia spiralis Dumort.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References