Acanthomintha obovata subsp. obovata
San benito thornmint, San Benito Thornmint, San Benito thorn-mint
Photo: parent species Acanthomintha obovata · (c) Trevor Van Loon, some rights reserved (CC BY) · licence
Family: Lamiaceae · Type: Herb · Native
Conservation status: CNPS 4.2
Acanthomintha obovata subsp. obovata (San benito thornmint) is a native California herb in the Lamiaceae family, recognized by differentiated by lack of strong smell/glandular coating and bract shape.
San benito thornmint is a rare (CNPS 4.2) California native annual found in the South-Central Coast Interior bioregion in grassy slopes, oak woodland, and chaparral, often on vertic clay or occasionally serpentine areas at elevations below 1,600 meters. Flowering from April to July, this plant produces small, delicate flowers with distinctive white to lavender petals nestled among spiny bracts. Growing with slender stems covered in short to long hairs, some inconspicuously glandular, it forms compact clusters that blend into its grassland habitat. Its leaves are small and textured, typically arranged in a way that highlights the plant's intricate structural details. The flowers feature anthers moderately covered in woolly hairs, giving the plant a soft yet prickly appearance characteristic of its thornmint lineage.
Identification and appearance
Key characters: 2 sympatric species; differentiated by lack of strong smell/glandular coating and bract shape
Habitat and range
Habitat: Grassy slopes, oak woodland, chaparral, vertic clay, occasionally serpentine
Elevation: < 1600 m
California counties: San Benito, Ventura, Monterey, Fresno
Bloom period
Acanthomintha obovata subsp. obovata blooms Apr-Jul.
Conservation status
CNPS 4.2
How to tell it apart
vs Lycopus: Acanthomintha has spiny flower bracts and grows in dry grasslands, while Lycopus lacks spines and grows in wetlands.; vs Salvia: Acanthomintha has prominent spiny-margined bracts beneath flowers, while Salvia has plain bracts.; vs Monarda: Acanthomintha is annual with spiny bracts, while Monarda is perennial with smooth bracts.; vs Hedeoma: Acanthomintha is annual with spiny bracts, while Hedeoma is perennial with smooth bracts and swollen calyx.; vs Pogogyne: Acanthomintha has spiny-margined bracts, while Pogogyne has smooth bracts and densely head-like flower clusters.
Frequently asked questions
Is Acanthomintha obovata subsp. obovata native to California?
Yes. Acanthomintha obovata subsp. obovata is native to California (recorded as native).
When does Acanthomintha obovata subsp. obovata bloom?
Acanthomintha obovata subsp. obovata blooms Apr-Jul.
Where in California does Acanthomintha obovata subsp. obovata grow?
Acanthomintha obovata subsp. obovata occurs in San Benito, Ventura, Monterey, Fresno, at elevations of < 1600 m.
What plant family does Acanthomintha obovata subsp. obovata belong to?
Acanthomintha obovata subsp. obovata is in the Lamiaceae family, genus Acanthomintha.
Is Acanthomintha obovata subsp. obovata rare or endangered?
Acanthomintha obovata subsp. obovata carries California Rare Plant Rank 4.2, state rank S3S4.
Related species
Other California species in the same genus, family, or bioregion.
- Acanthomintha sp. — Thornmint
- Acanthomintha duttonii — San mateo thornmint
- Acanthomintha ilicifolia — San diego thornmint
- Acanthomintha lanceolata — Santa clara thornmint
- Acanthomintha obovata — Obvate-leafed thorn mint
- Acanthomintha obovata subsp. cordata — Heart-leaved thornmint
- Agastache parvifolia — Small leaved horsemint
- Agastache sp. — Horsemint
- Agastache urticifolia — Horse mint
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.