Asclepias asperula subsp. asperula
Antelope-horns, Antelope-Horns, antelope-horns
Wing-Chi Poon (via Wikimedia Commons) · CC BY-SA
Family: Apocynaceae · Type: Herb · Native
Conservation status: CNPS 4.3
Asclepias asperula subsp. asperula (Antelope-horns) is a native California herb in the Apocynaceae family, recognized by distinctive dark purple hoods not elevated above corolla.
Antelope-horns is a California native perennial found in the eastern Mojave Desert in dry, open, rocky places at elevations of 1,500 to 2,000 meters. Flowering from March to September, this plant produces green-white flowers with distinctive dark purple hoods and compact clusters on terminal stems. Growing with decumbent to ascending stems 15 to 45 centimeters tall that are slightly hairy, it develops a sparse, open structure. Its leaves are alternate or sometimes arranged in groups of three, with narrow linear-lanceolate blades that spread along the stem. The plant produces distinctive erect fruits with reflexed pedicels, each containing seeds 6 to 8 millimeters long.
Identification and appearance
Key characters: 9 sympatric species; distinctive dark purple hoods not elevated above corolla
Habitat and range
Habitat: Dry, open, rocky places
Elevation: 1500-2000 m
California counties: San Bernardino
Outside California: southwestern United States, Mexico
Bloom period
Asclepias asperula subsp. asperula blooms Mar-Sep.
Conservation status
CNPS 4.3
How to tell it apart
vs Gomphocarpus: Asclepias has hoods that touch or nearly touch at their edges; Gomphocarpus has gaps between hood edges.; vs Erigeron: Asclepias has rounded umbel clusters with large individual flowers; Erigeron has daisy-like flowers with many thin ray petals.; vs Lantana: Asclepias has reflexed petals with a raised hood crown; Lantana has flat-faced tubular flowers in dense rounded heads.; vs Apocynum: Asclepias has large showy flowers in dome-shaped clusters; Apocynum has tiny bell-shaped flowers in branched sprays.; vs Baccharis: Asclepias has milky sap and large distinctive flowers; Baccharis has clear sap and tiny fuzzy composite flowers.
Frequently asked questions
Is Asclepias asperula subsp. asperula native to California?
Yes. Asclepias asperula subsp. asperula is native to California (recorded as native).
When does Asclepias asperula subsp. asperula bloom?
Asclepias asperula subsp. asperula blooms Mar-Sep.
Where in California does Asclepias asperula subsp. asperula grow?
Asclepias asperula subsp. asperula occurs in San Bernardino, at elevations of 1500-2000 m.
What plant family does Asclepias asperula subsp. asperula belong to?
Asclepias asperula subsp. asperula is in the Apocynaceae family, genus Asclepias.
Is Asclepias asperula subsp. asperula rare or endangered?
Asclepias asperula subsp. asperula carries California Rare Plant Rank 4.3, state rank S3.
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.