Sporobolus densiflorus
Dense-flowered cord grass
(c) Sam Kieschnick, some rights reserved (CC BY), uploaded by Sam Kieschnick · licence
Family: Poaceae · Type: Grass · Not Native
Conservation status: Cal-IPC Yes
Sporobolus densiflorus (Dense-flowered cord grass) is a non-native California grass in the Poaceae family, recognized by compact inflorescence, narrow inrolled leaves, bristly keels.
Dense-flowered cord grass is a naturalized perennial found in the northern and central California Coast bioregions in coastal salt marshes at elevations below 10 meters. Flowering from May to August, this plant produces small, dense inflorescences with overlapping branches 6 to 30 centimeters long. Growing in clumps with slender stems 27 to 150 centimeters tall, it forms tightly clustered tufts with firm internodes. Its leaves are narrow, 12 to 43 centimeters long, typically inrolled when fresh, with approximately two ridges per millimeter on the upper surface. The plant's spikelets are distinctive, measuring 8 to 14 millimeters long with short, sharp-bristly keels on both glumes and lemmas.
Identification and appearance
Key characters: 6 sympatric species; key features are compact inflorescence, narrow inrolled leaves, bristly keels
Habitat and range
Habitat: Coastal salt marshes
Elevation: < 10 m
California counties: Humboldt, Contra Costa, Marin, Del Norte, Solano
Outside California: native to southern South America
Bloom period
Sporobolus densiflorus blooms May-Aug.
Conservation status
Cal-IPC Yes
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 densiflorus native to California?
No. Sporobolus densiflorus is not native to California (recorded as not native).
When does Sporobolus densiflorus bloom?
Sporobolus densiflorus blooms May-Aug.
Where in California does Sporobolus densiflorus grow?
Sporobolus densiflorus occurs in Humboldt, Contra Costa, Marin, Del Norte, Solano, at elevations of < 10 m.
What plant family does Sporobolus densiflorus belong to?
Sporobolus densiflorus is in the Poaceae family, genus Sporobolus.
Is Sporobolus densiflorus invasive in California?
Sporobolus densiflorus is listed by Cal-IPC with an invasiveness rating of Yes.
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.