Streptanthus polygaloides
Milkwort jewelflower
(c) Ken-ichi Ueda, some rights reserved (CC BY) · licence
Family: Brassicaceae · Type: Herb · Native
Streptanthus polygaloides (Milkwort jewelflower) is a native California herb in the Brassicaceae family, recognized by distinctive bilateral flowers with banner-like upper sepal.
Milkwort jewelflower is a native annual found in the northern Sierra Nevada Foothills and northern Sierra Nevada in serpentine barrens, chaparral openings, and sparse pine and cypress woodland at elevations of 200 to 1,100 meters. Flowering from May to July, this plant produces white petals with distinctive red-purple veins in delicate, bilateral flowers with a unique banner-like hood formed by the upper sepals. Growing 2 to 8 decimeters tall with simple or branched stems, it displays an elegant structure with basal rosette leaves that are early-deciduous and wavy-dentate. Its leaves transition from broadly linear basal rosettes to thin, sessile linear cauline leaves with entire margins and occasionally lobed bases. The fruit is a slender, straight pendant pod 2.4 to 5.6 centimeters long, bearing 18 to 50 small oblong seeds with narrow wing margins.
Identification and appearance
Key characters: 22 sympatric species; distinctive bilateral flowers with banner-like upper sepal
Habitat and range
Habitat: Serpentine barrens, chaparral openings, sparse pine/cypress woodland
Elevation: 200-1100 m.
California counties: Mariposa, Amador, Butte, Calaveras, Placer, Sierra, Tuolumne, Fresno, Nevada, El Dorado, Siskiyou, Plumas
Bloom period
Streptanthus polygaloides blooms May-Jul.
How to tell it apart
vs Caulanthus: Seed pods are flattened like sword blades versus cylindrical tubes in Caulanthus.; vs Boechera: Robust plants often over 2.5 feet with large flowers (sepals 4-8mm) versus more delicate habit.; vs Claytonia: Mustard family with 4 petals and 6 stamens versus Claytonia with 5 petals.; vs Silene: Mustard family with seed pods versus Silene with inflated capsules and opposite leaves.; vs Lonicera: Herbaceous mustard with alternate leaves versus woody vine with opposite leaves.
Frequently asked questions
Is Streptanthus polygaloides native to California?
Yes. Streptanthus polygaloides is native to California (recorded as native).
When does Streptanthus polygaloides bloom?
Streptanthus polygaloides blooms May-Jul.
Where in California does Streptanthus polygaloides grow?
Streptanthus polygaloides occurs in Mariposa, Amador, Butte, Calaveras, Placer, Sierra, Tuolumne, Fresno and other counties, at elevations of 200-1100 m..
What plant family does Streptanthus polygaloides belong to?
Streptanthus polygaloides is in the Brassicaceae family, genus Streptanthus.
What habitat does Streptanthus polygaloides grow in?
Streptanthus polygaloides grows in Serpentine barrens, chaparral openings, sparse pine/cypress woodland.
Related species
Other California species in the same genus, family, or bioregion.
- Streptanthus polygaloides subsp. alternans — Tuolumne jewelflower
- Streptanthus polygaloides subsp. aureus — Golden jewelflower
- Streptanthus polygaloides subsp. bicolor — Red hills jewelflower
- Streptanthus polygaloides subsp. liber
- Streptanthus polygaloides subsp. polygaloides
- Streptanthus polygaloides subsp. purpureus — Purple milkwort jewelflower
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.