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Taxon  Report  
Streptanthus callistus  J. L. Morrison
Mt. hamilton jewel flower,   Mt. hamilton jewelflower
Streptanthus callistus is an annual herb that is native to California, and endemic (limited) to California.
California Rare Plant Rank: 1B.3 (rare, threatened, or endangered in CA and elsewhere).
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Observation Search
(27 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

Communities: Foothill Woodland, Chaparral
Name Status:
Accepted by JEF + CNPS + PLANTS

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


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[Wikipedia] Description, Rarity: Streptanthus callistus is a rare species of flowering plant in the mustard family known by the common name Mount Hamilton jewelflower.[1] It is endemic to Santa Clara County, California, where it is known from only about five occurrences around Mount Hamilton.[2] It grows in chaparral and woodlands and on dry scree. It is an annual herb producing a small stem up to 8 or 9 centimeters tall with a bristly base. The toothed oval leaves are under 2 centimeters long. The inflorescence is a cluster-like raceme of flowers, the top ones sterile. The fertile flowers on the lower raceme have calyces of bristly purple-green sepals under a centimeter long with flaring purple petals at the tip. The sterile flowers at the top of the raceme have narrow, elongated, hairless purple sepals. The fruit is a cylindrical, bristle-studded silique measuring up to 2 or 2.5 centimeters long. (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: 12/01/2023).