Ruppia cirrhosa (Petagna) Grande
spiral ditch-grass (spiral ditchgrass)
Ruppiaceae (Ditch-grass family)
Introduction to Vascular Plants
spiral ditch-grass (spiral ditchgrass)
Ruppiaceae (Ditch-grass family)
Introduction to Vascular Plants
Species Information
General:
Perennial, aquatic herb from fibrous roots, rooting at the nodes; stems 30-80 cm long.
Leaves:
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.
Flowers:
Inflorescence on spirally coiled, axillary stalks, the coils 5 to 30, the stalks 0.2-2.5 cm long; petals lacking; stamens 2.
Fruits:
Nut-like, egg-shaped, 1.5-2 mm long; beaks lateral, erect, 0.5-1 mm long.
Notes:
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.
Illustration
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
Habitat and 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.Status Information
Synonyms
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.