Aristida purpurea var. longiseta
Red three-awn
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Family: Poaceae · Type: Grass · Native
Aristida purpurea var. longiseta (Red three-awn) is a native California grass in the Poaceae family, recognized by Very long awns (to 40-140 mm) and long glumes (upper 16-25 mm); branches drooping distally.
Red three-awn is a California native perennial found in the San Bernardino Mountains and desert regions on disturbed ground, dry slopes, plains, and shrubland at elevations below 1,800 meters. Flowering from May to November, this plant produces reddish-purple flowers with delicate, drooping grass-like inflorescences up to 15 centimeters long. Growing with slender stems 30 to 60 centimeters tall, it forms tufted clumps characteristic of bunch grasses. Its leaf blades are 4 to 16 centimeters long, with distinctive three-parted awns (hair-like bristles) that can extend 40 to 140 millimeters from each seed. The plant's dramatic, hair-like awns create a feathery, wind-catching appearance that helps disperse its seeds across arid landscapes.
Identification and appearance
Key characters: Very long awns (to 40-140 mm) and long glumes (upper 16-25 mm); branches drooping distally
Habitat and range
Habitat: Disturbed ground, dry slopes, plains, shrubland
Elevation: < 1800 m
Outside California: to southwestern Canada, northern Mexico
Bloom period
Aristida purpurea var. longiseta blooms May-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. longiseta native to California?
Yes. Aristida purpurea var. longiseta is native to California (recorded as native).
When does Aristida purpurea var. longiseta bloom?
Aristida purpurea var. longiseta blooms May-Nov.
What plant family does Aristida purpurea var. longiseta belong to?
Aristida purpurea var. longiseta is in the Poaceae family, genus Aristida.
What habitat does Aristida purpurea var. longiseta grow in?
Aristida purpurea var. longiseta grows in Disturbed ground, dry slopes, plains, shrubland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.