Streptanthus albidus
Encyclopedia
Streptanthus albidus is a species of flowering plant in the mustard family
known by the common name Metcalf Canyon jewelflower. It is endemic to California
, where it is known only from the Central Coast Ranges and San Francisco Bay Area
. It grows in open areas such as grassland
s, often on serpentine soil
s.
. Leaves farther up the stem are smaller and narrower, sometimes linear in shape, and toothed or smooth-edged. Flowers occur at intervals along the upper stem. Each has a spherical to urn-shaped calyx of keeled sepal
s about a centimeter long with curving petals emerging from the tip. The calyx of sepals may be white to purple, depending on subspecies. The fruit is a long, narrow silique
which may be 12 centimeters in length.
Brassicaceae
Brassicaceae, a medium sized and economically important family of flowering plants , are informally known as the mustards, mustard flowers, the crucifers or the cabbage family....
known by the common name Metcalf Canyon jewelflower. It is endemic to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, where it is known only from the Central Coast Ranges and San Francisco Bay Area
San Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
. It grows in open areas such as grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
s, often on serpentine soil
Serpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
s.
Description
It is an annual herb producing an erect, usually branching stem up to a meter tall or slightly taller. There are bristly hairs around the base. The basal leaves are lance-shaped with toothed edges and are borne on winged petiolesPetiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. Leaves farther up the stem are smaller and narrower, sometimes linear in shape, and toothed or smooth-edged. Flowers occur at intervals along the upper stem. Each has a spherical to urn-shaped calyx of keeled sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s about a centimeter long with curving petals emerging from the tip. The calyx of sepals may be white to purple, depending on subspecies. The fruit is a long, narrow silique
Silique
A silique or siliqua is a fruit of 2 fused carpels with the length being more than three times the width. The outer walls of the ovary usually separate when ripe, leaving a persistent partition...
which may be 12 centimeters in length.
Subspecies
There are two subspecies, both rare.- The rarer of the two, ssp. albidus, is federally listed as an endangered speciesEndangered speciesAn endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
of the United States. It is endemic to Santa Clara CountySanta Clara County, CaliforniaSanta Clara County is a county located at the southern end of the San Francisco Bay Area in the U.S. state of California. As of 2010 it had a population of 1,781,642. The county seat is San Jose. The highly urbanized Santa Clara Valley within Santa Clara County is also known as Silicon Valley...
, where it is known from nine recent occurrences. This subspecies has white or green-tinged sepals. - The other subspecies, ssp. peramoenus, the most beautiful jewelflower or uncommon jewelflower, is known from several locations in the Bay Area and several near San Luis ObispoSan Luis Obispo, CaliforniaSan Luis Obispo is a city in California, located roughly midway between San Francisco and Los Angeles on the Central Coast. Founded in 1772 by Spanish Fr. Junipero Serra, San Luis Obispo is one of California’s oldest communities...
. It has pale to dark purple sepals and purplish petals.