Ruppia cirrhosa
Ditch grass
(c) Duarte Frade, some rights reserved (CC BY) · licence
Family: Ruppiaceae · Type: Herb · Native
Ruppia cirrhosa (Ditch grass) is a native California herb in the Ruppiaceae family.
Ditch grass is a California native perennial found in coastal, valley, and desert regions including the North Coast, Central Western California, South Coast, San Bernardino Mountains, Great Basin, and Desert bioregions in freshwater marshes, ponds, and sloughs at elevations below 2,045 meters. Flowering from April to July, this aquatic plant produces small, inconspicuous greenish flowers. Growing submerged in water with slender, branching stems that can extend up to several meters in length, it forms dense underwater meadows. Its thin, linear leaves are narrow and grass-like, emerging directly from the stems and floating or waving with water currents. The plant reproduces both sexually and through vegetative spread, allowing it to colonize diverse aquatic habitats efficiently.
Identification and appearance
Key characters: 1 sympatric species (R. maritima). Key differentiators are elevation range and habitat salinity preferences.
Habitat and range
Habitat: Freshwater marshes, ponds, sloughs
Elevation: < 2045 m
Outside California: to Alaska, east-central United States, +- worldwide
Bloom period
Ruppia cirrhosa blooms Apr-Jul.
How to tell it apart
vs Zannichellia: Ruppia has umbrella-like fruit clusters on long stalks; Zannichellia has fruits sessile in leaf axils.; vs Stuckenia: Ruppia fruits are on long thread-like stalks in umbels; Stuckenia has fruits in dense spikes.; vs Sparganium: Ruppia has thread-like leaves and umbel fruit clusters; Sparganium has stiff leaves and spherical bur-like heads.; vs Myriophyllum: Ruppia has simple ribbon-like leaves; Myriophyllum has feathery divided leaves in whorls.; vs Najas: Ruppia has smooth-edged leaves; Najas has toothed leaf margins.
Frequently asked questions
Is Ruppia cirrhosa native to California?
Yes. Ruppia cirrhosa is native to California (recorded as native).
When does Ruppia cirrhosa bloom?
Ruppia cirrhosa blooms Apr-Jul.
What plant family does Ruppia cirrhosa belong to?
Ruppia cirrhosa is in the Ruppiaceae family, genus Ruppia.
What habitat does Ruppia cirrhosa grow in?
Ruppia cirrhosa grows in Freshwater marshes, ponds, sloughs.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.