Streptanthus glandulosus subsp. sonomensis
Uncommon jewelflower, Uncommon Jewelflower
(c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda · licence
Family: Brassicaceae · Type: Annual · Native
Streptanthus glandulosus subsp. sonomensis (Uncommon jewelflower) is a native California annual in the Brassicaceae family, recognized by cream/pale yellow sepals and lack of purple veining diagnostic.
Uncommon jewelflower is a California native annual found in central Sonoma County on serpentine outcrops at approximately 300 meters elevation. Flowering from May to July, this plant produces cream or pale yellow flowers 10 to 17 millimeters long with delicate, slightly veined petals. Growing 2.3 to 7 meters tall with bristly stems that become smoother toward the top, it has a distinctive one-sided flowering structure. Its cauline leaves are bristly, with upper leaves remaining entire or finely toothed along the edges. The fruit spreads in an arched formation, adding to the plant's unique architectural appearance.
Identification and appearance
Key characters: 5 sympatric species - cream/pale yellow sepals and lack of purple veining diagnostic
Habitat and range
Habitat: Serpentine outcrops
Elevation: +- 300 m.
Bloom period
Streptanthus glandulosus subsp. sonomensis 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 glandulosus subsp. sonomensis native to California?
Yes. Streptanthus glandulosus subsp. sonomensis is native to California (recorded as native).
When does Streptanthus glandulosus subsp. sonomensis bloom?
Streptanthus glandulosus subsp. sonomensis blooms May-Jul.
What plant family does Streptanthus glandulosus subsp. sonomensis belong to?
Streptanthus glandulosus subsp. sonomensis is in the Brassicaceae family, genus Streptanthus.
What habitat does Streptanthus glandulosus subsp. sonomensis grow in?
Streptanthus glandulosus subsp. sonomensis grows in Serpentine outcrops.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.