Streptanthus oliganthus
Masonic mountain jewelflower, Masonic Mountain Jewelflower
(c) Jim Morefield, some rights reserved (CC BY) · licence
Family: Brassicaceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Streptanthus oliganthus (Masonic mountain jewelflower) is a native California herb in the Brassicaceae family, recognized by distinctive high-elevation habitat and purple flowers.
Masonic mountain jewelflower is a rare (CNPS 1B.2) California native perennial found in central Sierra Nevada, northern Sierra Nevada, and northern White and Inyo Mountains in dry pinyon woodland, pine forest, rocky subalpine forest, and sagebrush scrub at elevations of 2,000 to 3,050 meters. Flowering from June to August, this plant produces maroon-purple flowers approximately 9 to 12 millimeters long with thin petals. Growing with simple or few-branched stems 15 to 40 centimeters tall, it forms a basal rosette of obovate leaves. Its leaves are distinctively arranged with basal rosette leaves entire and obovate, while mid-stem leaves are lance-oblong, 2.5 to 8 centimeters long, with a lobed base and obtuse to acute tip. The fruit develops as an ascending-spreading silique 4.5 to 9.7 centimeters long with 48 to 60 small seeds.
Identification and appearance
Key characters: 20 sympatric species; distinctive high-elevation habitat and purple flowers
Habitat and range
Habitat: Dry, open pinyon woodland, pine forest, rocky subalpine forest, sagebrush scrub
Elevation: 2000-3050 m
California counties: Mono, Inyo, Tuolumne
Outside California: west-central Nevada
Bloom period
Streptanthus oliganthus blooms Jun-Aug.
Conservation status
CNPS 1B.2
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 oliganthus native to California?
Yes. Streptanthus oliganthus is native to California (recorded as native).
When does Streptanthus oliganthus bloom?
Streptanthus oliganthus blooms Jun-Aug.
Where in California does Streptanthus oliganthus grow?
Streptanthus oliganthus occurs in Mono, Inyo, Tuolumne, at elevations of 2000-3050 m.
What plant family does Streptanthus oliganthus belong to?
Streptanthus oliganthus is in the Brassicaceae family, genus Streptanthus.
Is Streptanthus oliganthus rare or endangered?
Streptanthus oliganthus carries California Rare Plant Rank 1B.2, state rank S3.
Related species
Other California species in the same genus, family, or bioregion.
- Streptanthus polygaloides — Milkwort jewelflower
- 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
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.