Aristida purpurea
Purple three awn
Photo by Chez Brungraber
Family: Poaceae · Type: Grass · Native
Aristida purpurea (Purple three awn) is a native California grass in the Poaceae family.
Purple three awn is a native perennial grass found in various California bioregions in grassland and open woodland habitats. Flowering from May to July, this plant produces purple-tinged flowers with delicate, thin glumes and three distinctive spreading awns. Growing 10 to 100 centimeters tall with generally erect, unbranched stems, it forms dense, sometimes compact clumps in dry landscapes. Its leaf blades are very narrow, typically 5 to 25 centimeters long and less than 2 millimeters wide, often tightly inrolled to conserve moisture in arid environments. The plant's characteristic three-awned seed heads provide excellent identification, with awns of nearly equal length creating a distinctive, feathery appearance.
Identification and appearance
Key characters: Geographically isolated; unclear range data in source
Habitat and range
California counties: Riverside, San Bernardino, Orange, San Diego, Imperial, Ventura, Inyo
How to tell it apart
vs Muhlenbergia: Aristida always has three awns per seed; Muhlenbergia has one awn or none.; vs Hilaria: Aristida has three awns on each spikelet; Hilaria has spikelets grouped in threes with single awns.; vs Bromus: Aristida's three thin straight awns are unmistakable; Bromus has single awns and papery seed coverings.; vs Schismus: Aristida has three long awns per seed; Schismus is a tiny annual with no awns at all.; vs Stipa: Aristida has three straight awns; Stipa has one twisted, bent awn.
Frequently asked questions
Is Aristida purpurea native to California?
Yes. Aristida purpurea is native to California (recorded as native).
Where in California does Aristida purpurea grow?
Aristida purpurea occurs in Riverside, San Bernardino, Orange, San Diego, Imperial, Ventura, Inyo.
What plant family does Aristida purpurea belong to?
Aristida purpurea is in the Poaceae family, genus Aristida.
Related species
Other California species in the same genus, family, or bioregion.
- Aristida purpurea var. fendleriana — Fendler three-awn
- Aristida purpurea var. longiseta — Red three-awn
- Aristida purpurea var. nealleyi — Nealley three-awn
- Aristida purpurea var. parishii — Parish three-awn
- Aristida purpurea var. purpurea — Purple three-awn
- Aristida purpurea var. wrightii — Wright three-awn
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.