Ruppia maritima
Ditch grass
(c) Forest and Kim Starr, some rights reserved (CC BY) · licence
Family: Ruppiaceae · Type: Herb · Native
Ruppia maritima (Ditch grass) is a native California herb in the Ruppiaceae family.
Ditch grass is a California native perennial found in northern coastal, southwestern San Joaquin Valley, central western, southern coastal, and Channel Islands regions in brackish or saline waters, marshes, ponds, and sloughs at elevations below 600 meters. Flowering from March to August, this aquatic plant produces small, subtle flowers characteristic of submersed aquatic vegetation. Growing with slender, elongated underwater stems that branch and spread through rhizomes, it forms dense underwater meadows in shallow marine and brackish environments. Its thin, linear leaves are translucent green, emerging directly from the stem and floating or submerged in water. The plant reproduces effectively in dynamic coastal and estuarine habitats, adapting to changing salinity and water conditions.
Identification and appearance
Key characters: 1 sympatric species (R. cirrhosa). Key differentiators are elevation range and salinity tolerance.
Habitat and range
Habitat: Brackish or saline waters, often coastal, marshes, ponds, sloughs
Elevation: < 600 m
Outside California: +- worldwide.
Bloom period
Ruppia maritima blooms Mar-Aug.
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 maritima native to California?
Yes. Ruppia maritima is native to California (recorded as native).
When does Ruppia maritima bloom?
Ruppia maritima blooms Mar-Aug.
What plant family does Ruppia maritima belong to?
Ruppia maritima is in the Ruppiaceae family, genus Ruppia.
What habitat does Ruppia maritima grow in?
Ruppia maritima grows in Brackish or saline waters, often coastal, marshes, ponds, sloughs.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.