Boechera peirsonii
Peirson's rockcress, Peirson's Rockcress
Family: Brassicaceae · Type: Perennial · Native
Conservation status: CNPS 1B.2
Boechera peirsonii (Peirson's rockcress) is a native California perennial in the Brassicaceae family, recognized by . Key features: wide pods, limited high-elevation range, granitic substrate.
Peirson's rockcress is a rare (CNPS 1B.2) California native perennial found in the San Bernardino Mountains on granitic ledges and talus slopes at elevations of 2,700 to 3,350 meters. Flowering from June to September, this plant produces purple flowers 5 to 6 millimeters long with delicate petals about 1.5 to 2 millimeters wide. Growing with stems 10 to 25 centimeters tall emerging from a woody caudex, it develops from the center of a basal rosette with stems bearing short-stalked, branched hairs. Its basal leaves are 2.5 to 6 millimeters wide, covered with short 4 to 7-rayed hairs, while cauline leaves range from 3 to 12 in number with small basal lobes. The fruit develops as an ascending silique 2 to 3.7 centimeters long, containing 56 to 80 seeds arranged in a single row.
Identification and appearance
Key characters: 9 sympatric species. Key features: wide pods, limited high-elevation range, granitic substrate
Habitat and range
Habitat: Granitic ledges, talus slopes
Elevation: 2700-3350 m
California counties: San Bernardino, Alpine, Plumas
Bloom period
Boechera peirsonii blooms Jun-Sep.
Conservation status
CNPS 1B.2
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 peirsonii native to California?
Yes. Boechera peirsonii is native to California (recorded as native).
When does Boechera peirsonii bloom?
Boechera peirsonii blooms Jun-Sep.
Where in California does Boechera peirsonii grow?
Boechera peirsonii occurs in San Bernardino, Alpine, Plumas, at elevations of 2700-3350 m.
What plant family does Boechera peirsonii belong to?
Boechera peirsonii is in the Brassicaceae family, genus Boechera.
Is Boechera peirsonii rare or endangered?
Boechera peirsonii carries California Rare Plant Rank 1B.2, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.