Boechera lyallii
Lyall's rockcress
(c) Trevor Van Loon, some rights reserved (CC BY), uploaded by Trevor Van Loon · licence
Family: Brassicaceae · Type: Perennial · Native
Boechera lyallii (Lyall's rockcress) is a native California perennial in the Brassicaceae family, recognized by . Key features: alpine habitat, erect appressed fruits, purple flowers.
Lyall's rockcress is a California native perennial found in the Warner Mountains, Sierra Nevada, White and Inyo Mountains in alpine and subalpine habitats at elevations of 2,000 to 3,900 meters. Flowering from June to August, this plant produces lavender to purple flowers 6 to 8.5 millimeters long with petals 1.5 to 3 millimeters wide. Growing with slender stems 3 to 15 centimeters tall emerging from a woody caudex, it forms delicate rosettes near ground level. Its basal leaves are narrow, 1 to 5 millimeters wide, with simple or short-stalked hairs along the margins, while cauline leaves are sparse and glabrous. The fruits are slender, erect siliques 3 to 5.6 centimeters long, containing 34 to 64 seeds arranged in two rows.
Identification and appearance
Key characters: 30 sympatric species. Key features: alpine habitat, erect appressed fruits, purple flowers
Habitat and range
Habitat: Uncommon. Cliffs, talus slopes, gravelly soil, in alpine, subalpine habitats
Elevation: 2000-3900 m
California counties: El Dorado, Mono, Tuolumne, Inyo, Siskiyou, Tulare, Fresno, Modoc, Alpine, Plumas, Nevada, Placer, Trinity
Outside California: to Alaska, Utah
Bloom period
Boechera lyallii blooms Jun-Aug.
How to tell it apart
vs Arabis: Boechera pods hang downward or curve and are wider (2mm+); Arabis pods stand rigidly erect and are narrower.; vs Matthiola: Boechera has flattened pods; Matthiola has cylindrical pods and densely hairy gray-green foliage.; vs Streptanthus: Boechera petals narrow gradually without a claw; Streptanthus petals have a distinct narrow claw at base.; vs Penstemon: Boechera has four-petaled flowers and seed pods; Penstemon has tubular five-lobed flowers.; vs Caulanthus: Boechera is perennial with a woody base; Caulanthus is typically annual or biennial without a woody caudex.
Frequently asked questions
Is Boechera lyallii native to California?
Yes. Boechera lyallii is native to California (recorded as native).
When does Boechera lyallii bloom?
Boechera lyallii blooms Jun-Aug.
Where in California does Boechera lyallii grow?
Boechera lyallii occurs in El Dorado, Mono, Tuolumne, Inyo, Siskiyou, Tulare, Fresno, Modoc and other counties, at elevations of 2000-3900 m.
What plant family does Boechera lyallii belong to?
Boechera lyallii is in the Brassicaceae family, genus Boechera.
What habitat does Boechera lyallii grow in?
Boechera lyallii grows in Uncommon. Cliffs, talus slopes, gravelly soil, in alpine, subalpine habitats.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.