Triglochin palustris
Marsh arrow-grass
(c) Dmitriy Bochkov, some rights reserved (CC BY) · licence
Family: Juncaginaceae · Type: Grass · Native
Conservation status: CNPS 2B.3
Triglochin palustris (Marsh arrow-grass) is a native California grass in the Juncaginaceae family, recognized by no sympatric species.
Marsh arrow-grass is a native perennial herb found in central Sierra Nevada Mountains in wet meadows, stream margins, and lake edges at elevations of 2,100 to 3,450 meters. Flowering from July to August, this plant produces small, inconspicuous greenish-white flowers in aerial racemes rising above its grass-like leaves. Growing in dense tufts with ascending rhizomes, it forms compact clusters 10 to 30 centimeters tall with slender, elliptical leaves. Its leaves are narrow, measuring 0.5 to 2 millimeters wide, with a distinctive deep two-lobed tip and no visible ligule. The fruit consists of three mericarps 5 to 7 millimeters long, which cling delicately to the central fruit axis.
Identification and appearance
Key characters: Geographically isolated from all congeners; no sympatric species
Habitat and range
Habitat: Wet meadows, wet flats, stream and lake margins
Elevation: 2100-3450 m
California counties: Tulare, Inyo, Mono, Fresno, Tuolumne
Outside California: circumboreal, South America, New Zealand
Bloom period
Triglochin palustris blooms Jul-Aug.
Conservation status
CNPS 2B.3
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 palustris native to California?
Yes. Triglochin palustris is native to California (recorded as native).
When does Triglochin palustris bloom?
Triglochin palustris blooms Jul-Aug.
Where in California does Triglochin palustris grow?
Triglochin palustris occurs in Tulare, Inyo, Mono, Fresno, Tuolumne, at elevations of 2100-3450 m.
What plant family does Triglochin palustris belong to?
Triglochin palustris is in the Juncaginaceae family, genus Triglochin.
Is Triglochin palustris rare or endangered?
Triglochin palustris carries California Rare Plant Rank 2B.3, state rank S2.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.