Sporobolus alterniflorus
Salt-water cord grass
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Family: Poaceae · Type: Grass · Not Native
Sporobolus alterniflorus (Salt-water cord grass) is a non-native California grass in the Poaceae family, recognized by massive size, thick stems, large open inflorescence.
Salt-water cord grass is a naturalized perennial found in coastal salt marshes of the San Francisco Bay area at elevations below 10 meters. Flowering from July to September, this plant produces small greenish-white flowers in open branching inflorescences 10 to 40 centimeters long. Growing in dense clumps with thick stems 6 to 25 decimeters tall and a robust rhizomatous base, it forms extensive maritime marsh communities. Its leaves are distinctive, with flat blades 20 to 55 centimeters long and 4 to 25 millimeters wide, featuring approximately six parallel ridges on the upper surface. The plant spreads through thick, short rhizomes and creates dense vegetative mats in coastal salt marsh environments.
Identification and appearance
Key characters: 6 sympatric species; key features are massive size, thick stems, large open inflorescence
Habitat and range
Habitat: Coastal salt marshes
Elevation: < 10 m
Outside California: native to eastern North America
Bloom period
Sporobolus alterniflorus blooms Jul-Sep.
How to tell it apart
vs Typha: Typha (cattails) has thick, sausage-like brown flower spikes and wide strap-like leaves, not grass flowers.; vs Distichlis: Distichlis forms stiff colonies in salt marshes with distinctly two-ranked leaves, lacking ciliate sheaths.; vs Muhlenbergia: Sporobolus has fringed hairs on leaf sheath margins; Muhlenbergia sheaths are smooth.; vs Leymus: Leymus has spike-like inflorescences with spikelets in pairs, not the open panicles of Sporobolus.; vs Oloptum: Oloptum has prominent bent awns and plumose hairs; Sporobolus is awnless with ciliate sheaths.
Frequently asked questions
Is Sporobolus alterniflorus native to California?
No. Sporobolus alterniflorus is not native to California (recorded as not native).
When does Sporobolus alterniflorus bloom?
Sporobolus alterniflorus blooms Jul-Sep.
What plant family does Sporobolus alterniflorus belong to?
Sporobolus alterniflorus is in the Poaceae family, genus Sporobolus.
What habitat does Sporobolus alterniflorus grow in?
Sporobolus alterniflorus grows in Coastal salt marshes.
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.