Thelypodium milleflorum
Many-flowered thelypodium
(c) Jim Morefield, some rights reserved (CC BY) · licence
Family: Brassicaceae · Type: Herb · Native
Conservation status: CNPS 2B.2
Thelypodium milleflorum (Many-flowered thelypodium) is a native California herb in the Brassicaceae family, recognized by hollow stem and appressed erect fruits.
Many-flowered thelypodium is a rare (CNPS 2B.2) California native biennial found in the Great Basin in sandy scrub habitats at elevations of 1,300 to 2,500 meters. Flowering from April to August, this plant produces white flowers in dense, spike-like inflorescences with oblanceolate petals 9 to 15 millimeters long. Growing 4.5 to 13 decimeters tall with a hollow stem, it develops a distinctive branching structure with glabrous stems except for ciliate petioles. Its basal leaves are 6 to 23 centimeters long with dentate edges, transitioning from petioled basal leaves to mid-cauline leaves with similar tooth-like lobing. The plant produces elongated cylindric fruits 3 to 8 centimeters long, with 50 to 78 small oblong seeds nestled within.
Identification and appearance
Key characters: 7 sympatric species; diagnostic hollow stem and appressed erect fruits
Habitat and range
Habitat: Sandy soils, scrub
Elevation: 1300-2500 m
California counties: Lassen, Modoc, Mono
Outside California: to southern British Columbia, Utah
Bloom period
Thelypodium milleflorum blooms Apr-Aug.
Conservation status
CNPS 2B.2
How to tell it apart
vs Stanleya: Flower stalks barely visible versus quarter-inch-plus dramatic stalks in Stanleya.; vs Caulanthus: Seed pods sit on distinct stalks above flower base versus sitting directly on base.; vs Brassica: Purple to white flowers with stalked pods versus yellow flowers in Brassica.; vs Boechera: Robust plants with relatively large flowers (6-16mm) versus delicate plants with smaller flowers.; vs Noccaea: Tall stems with purple-white flowers versus low rosette plants with tiny white flowers.
Frequently asked questions
Is Thelypodium milleflorum native to California?
Yes. Thelypodium milleflorum is native to California (recorded as native).
When does Thelypodium milleflorum bloom?
Thelypodium milleflorum blooms Apr-Aug.
Where in California does Thelypodium milleflorum grow?
Thelypodium milleflorum occurs in Lassen, Modoc, Mono, at elevations of 1300-2500 m.
What plant family does Thelypodium milleflorum belong to?
Thelypodium milleflorum is in the Brassicaceae family, genus Thelypodium.
Is Thelypodium milleflorum rare or endangered?
Thelypodium milleflorum carries California Rare Plant Rank 2B.2, state rank S3?.
Related species
Other California species in the same genus, family, or bioregion.
- Thelypodium sp.
- Thelypodium stenopetalum — Slender-petaled thelypodium
- Thelypodium brachycarpum — Short-podded thelypodium
- Thelypodium crispum — Crisped thelypody
- Thelypodium flexuosum — Nodding thelypodium
- Thelypodium howellii subsp. howellii — Howell's thelypodium
- Thlaspi arvense — Fan weed
- Thlaspi sp. — Pennycress
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.