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Taxon  Report  
Boechera johnstonii  (Munz) Al-Shehbaz
Johnston's rockcress
Boechera johnstonii is a perennial herb that is native to California, and endemic (limited) to California.
also called Arabis johnstonii
California Rare Plant Rank: 1B.2 (rare, threatened, or endangered in CA and elsewhere).
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial
Observation Search
~41 records in California
yellowone or more occurrences
within a 7.5-minute quadrangle

Bloom Period
Genus: Boechera
Family: Brassicaceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Communities: Yellow Pine Forest, Chaparral
Name Status:
Accepted by JEF + CNPS

Alternate Names:
JEFArabis hirshbergiae
JEF + CNPSArabis johnstonii
Information about  Boechera johnstonii from other sources
Nursery availability from CNPLX
Commercial availability unknown.
Jepson eFlora

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ID Tips on PlantID.net

[efloras.org] Description, Habitat, Range: Perennials; long-lived; (ces-pitose); sexual; caudex woody. Stems usually 1 per caudex branch, arising from center of rosette near ground surface, 0.5 to 2 dm, densely pubescent proximally, trichomes short-stalked, 4 to 10-rayed, 0.07 to 0.15 mm, sparsely to densely pubescent distally. Basal leaves: blade narrowly oblanceolate, 1.5 to 4 mm wide, margins entire, not ciliate, surfaces densely pubescent, trichomes short-stalked, 6 to 14-rayed, 0.07 to 0.15 mm. Cauline leaves: 4 to 10, often concealing stem proximally; blade auricles absent, surfaces of distalmost leaves densely pubescent. Racemes 10 to18 flowered, unbranched. Fruiting pedicels divaricate-ascending, straight, 5 to 14 mm, pubescent, trichomes appressed, branched. Flowers ascending at anthesis; sepals pubescent; petals purple, 9 to 14 by 2 to 4 mm, glabrous; pollen ellipsoid. Fruits divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 4 to 6 cm by 2.5 to 4 mm; valves glabrous; ovules 26 to 34 per ovary. Flowering Feb. to Mar. Rocky areas and gravelly soil in chaparral and oak-pine savannas; of conservation concern; 1300 to 1700 m; Calif. Boechera johnstonii and B. hirshbergiae are too similar to be considered distinct species. Even with the expanded circumscription, this distinctive sexual species is known only from the area of Cuyamaca Lake (San Diego County) and the San Jacinto Mountains (Riverside County). (link added by Mary Ann Machi)

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 07/17/2024).