Stipa chaetophora
Stipoid rice grass
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Family: Poaceae · Type: Grass · Not Native
Stipa chaetophora (Stipoid rice grass) is a non-native California grass in the Poaceae family, recognized by dark shiny lemma and geographic restriction.
Stipoid rice grass is a naturalized perennial found in the central California coast near Marin County in meadows, open woodland, and disturbed areas at elevations of 100 to 120 meters. Flowering from May to June, this grass produces narrow, fine inflorescences with delicate spikelets 4 to 8 millimeters long. Growing with slender stems 20 to 60 centimeters tall, it has fine, thread-like leaf blades less than half a millimeter wide and extending 14 to 30 centimeters in length. Its leaf sheaths are glabrous distally with minute bristly textures, while the lemmas are dark brown to black with a shiny surface and a distinctive bent awn 15 to 25 millimeters long. The palea is uniquely grooved lengthwise and late-deciduous, contributing to the grass's delicate appearance.
Identification and appearance
Key characters: 6 sympatric species; dark shiny lemma and geographic restriction are diagnostic
Habitat and range
Habitat: Meadows, open woodland, disturbed areas
Elevation: 100-120 m
California counties: Marin
Outside California: native to South America
Bloom period
Stipa chaetophora blooms May-Jun.
How to tell it apart
vs Nassella: Nassella has feathery plumose awns; Stipa awns are scabrous (rough) not plumose.; vs Oloptum: Oloptum has twice-bent awns with dense crown; Stipa has once-bent awns.; vs Eriocoma: Eriocoma has densely hairy lemmas; Stipa lemmas are smooth to scabrous.; vs Pappostipa: Pappostipa has plumose awns; Stipa awns are rough but not feathery.; vs Bromus: Bromus has multiple-flowered spikelets; Stipa has single-flowered spikelets with bent awns.
Frequently asked questions
Is Stipa chaetophora native to California?
No. Stipa chaetophora is not native to California (recorded as not native).
When does Stipa chaetophora bloom?
Stipa chaetophora blooms May-Jun.
Where in California does Stipa chaetophora grow?
Stipa chaetophora occurs in Marin, at elevations of 100-120 m.
What plant family does Stipa chaetophora belong to?
Stipa chaetophora is in the Poaceae family, genus Stipa.
What habitat does Stipa chaetophora grow in?
Stipa chaetophora grows in Meadows, open woodland, disturbed areas.
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.