Aristida purpurea var. purpurea
Purple three-awn
Photo by Chez Brungraber
Family: Poaceae · Type: Grass · Native
Aristida purpurea var. purpurea (Purple three-awn) is a native California grass in the Poaceae family.
Purple three-awn is a native perennial grass found in southern California coastal areas, San Bernardino Mountains, Peninsular Ranges, and Desert Mountains on dry slopes and shrublands at elevations below 1,500 meters. Flowering from February to November, this grass produces purple-tinted inflorescences with delicate, thread-like branches that curve into distinctive S- or U-shaped arrangements. Growing with slender stems 20 to 50 centimeters tall, it develops graceful, arching culms that create an elegant, wispy appearance. Its leaf blades range from 3 to 17 centimeters long, with characteristic fine, thread-like awns extending 20 to 60 millimeters from each spikelet. The grass produces intricate spikelets with lower glumes 4 to 9 millimeters long and delicate, curving awns that give the plant its distinctive, airy texture.
Habitat and range
Habitat: dry slopes, shrubland
Elevation: < 1500 m
California counties: San Bernardino, Inyo, Los Angeles, Mono, Orange, Riverside, San Diego, Imperial
Outside California: to Arkansas, northern Mexico
Bloom period
Aristida purpurea var. purpurea blooms Feb-Nov.
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 var. purpurea native to California?
Yes. Aristida purpurea var. purpurea is native to California (recorded as native).
When does Aristida purpurea var. purpurea bloom?
Aristida purpurea var. purpurea blooms Feb-Nov.
Where in California does Aristida purpurea var. purpurea grow?
Aristida purpurea var. purpurea occurs in San Bernardino, Inyo, Los Angeles, Mono, Orange, Riverside, San Diego, Imperial, at elevations of < 1500 m.
What plant family does Aristida purpurea var. purpurea belong to?
Aristida purpurea var. purpurea is in the Poaceae family, genus Aristida.
What habitat does Aristida purpurea var. purpurea grow in?
Aristida purpurea var. purpurea grows in dry slopes, shrubland.
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.