Streptanthus batrachopus
Encyclopedia
Streptanthus batrachopus is a rare species of flowering plant in the mustard family
known by the common name Mt. Tamalpais jewelflower. It is endemic to Marin County, California
, where it is known only from Mt. Tamalpais
and surrounding terrain. There are fewer than ten known occurrences.
Its habitat includes chaparral
and coniferous forest, generally on serpentine soil
s.
Flowers occur at intervals along the upper stem. Each has an urn-shaped calyx of purple or greenish sepal
s up to half a centimeter long. Purple or purple-streaked white petals emerge from the tip. The fruit is a straight or curving silique
up to 3 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 Mt. Tamalpais jewelflower. It is endemic to Marin County, California
Marin County, California
Marin County is a county located in the North San Francisco Bay Area of the U.S. state of California, across the Golden Gate Bridge from San Francisco. As of 2010, the population was 252,409. The county seat is San Rafael and the largest employer is the county government. Marin County is well...
, where it is known only from Mt. Tamalpais
Mount Tamalpais
Mount Tamalpais is a peak in Marin County, California, United States, often considered symbolic of Marin County. Much of Mount Tamalpais is protected within public lands such as Mount Tamalpais State Park and the Mount Tamalpais Watershed.-Geography:...
and surrounding terrain. There are fewer than ten known occurrences.
Its habitat includes chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
and coniferous forest, generally 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 a branching or unbranched stem up to about 20 centimeters in maximum height or slightly taller. Leaves near the base of the stem are oval or lance-shaped with toothed edges, somewhat fleshy in texture with a mottled pattern, and no more than 2 to 3 centimeters long. Leaves farther up the stem are lance-shaped.Flowers occur at intervals along the upper stem. Each has an urn-shaped calyx of purple or greenish 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 up to half a centimeter long. Purple or purple-streaked white petals emerge from the tip. The fruit is a straight or curving 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...
up to 3 centimeters in length.