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Taxon  Report  
Streptanthus howellii  S. Watson
Howell's jewel flower,   Howell's jewelflower
Streptanthus howellii is a perennial herb that is native to California, and also found in Oregon.
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
(26 records)
yellowone or more occurrences
within a 7.5-minute quadrangle

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

Ultramafic affinity: 6 - strict endemic

Communities: Yellow Pine Forest

Name Status:
Accepted by JEF + CNPS + PLANTS

Information about  Streptanthus howellii from other sources
Nursery availability from CNPLX
Commercial availability unknown.
Jepson eFlora


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[Wikipedia] Description, Range, Threats: Streptanthus howellii is an uncommon species of flowering plant in the mustard family known by the common name Howell's jewelflower.[1] It is endemic to the Klamath Mountains of southern Oregon and northern California. It grows in mountain forests on serpentine soils. It is a perennial herb producing a hairless, often waxy-textured stem up to 70 or 80 centimeters in maximum length. It is generally unbranched. The ephemeral basal leaves have fleshy oval blades with smooth or toothed edges, borne on petioles. Leaves farther up the stem are similar but smaller and narrower, with shorter petioles or none. They do not clasp the stem. Flowers occur at intervals along the upper stem. Each has a calyx of purple sepals under a centimeter long with purple-tipped yellow petals emerging from the tip. The fruit is a thin, smooth, curved silique up to 12 centimeters long. This rare plant is threatened by wildfire suppression; it would be more common if its habitat were allowed its natural fire regime.[2] It is also threatened by mining operations.[3] (contributed 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]. 2023. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 11/30/2023).