Triglochin concinna
Arrow grass
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Family: Juncaginaceae · Type: Grass · Native
Triglochin concinna (Arrow grass) is a native California grass in the Juncaginaceae family, recognized by no sympatric species.
Arrow grass is a California native perennial found in wet coastal meadows and salt marshes, forming loose tufts or mats at low elevations. Flowering from spring to early summer, this plant produces small greenish-white flowers in slender aerial racemes rising above its narrow leaves. Growing 10 to 60 centimeters tall with creeping rhizomes, it develops thin, round or semicircular stems that spread into loose clusters. Its leaves are fine and grass-like, typically 5 to 30 centimeters long and only 1 to 2 millimeters wide, with deeply two-lobed leaf tips. The fruit consists of six slender mericarps 3 to 6 millimeters long that fully separate when mature.
Identification and appearance
Key characters: Geographically isolated from all congeners; no sympatric species
Habitat and range
California counties: Marin, Alameda, Orange, San Luis Obispo, Santa Barbara, Siskiyou, Mono, Shasta, Inyo, Humboldt, Los Angeles, Solano, San Diego, Ventura
How to tell it apart
vs Plantago: Triglochin has bractless flower spikes with scale-like flowers; Plantago has obvious leafy bracts below the flower cluster.; vs Typha: Triglochin has a slender spike of tiny greenish flowers; Typha has dense, brown, sausage-shaped flower heads.; vs Juncus: Triglochin leaves are semicircular in cross-section with a groove above; Juncus leaves are round or flat without a groove.; vs Rumex: Triglochin leaves are undivided grass-like blades; Rumex has broader leaves with a distinct midvein and papery sheaths.; vs Lomandra: Triglochin has tiny greenish flowers in a slender spike; Lomandra has larger cream-yellow flowers in dense clusters.
Frequently asked questions
Is Triglochin concinna native to California?
Yes. Triglochin concinna is native to California (recorded as native).
Where in California does Triglochin concinna grow?
Triglochin concinna occurs in Marin, Alameda, Orange, San Luis Obispo, Santa Barbara, Siskiyou, Mono, Shasta and other counties.
What plant family does Triglochin concinna belong to?
Triglochin concinna is in the Juncaginaceae family, genus Triglochin.
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.