Streptanthus vernalis
Encyclopedia
Streptanthus vernalis is a rare species of flowering plant in the mustard family
known by the common name early jewelflower. It was first observed in the 1970s but not actually described to science until 2005. It is endemic to Lake County, California
, where it is known from a single occurrence at Three Peaks near the Napa County
line. It is apparently limited to serpentine outcrops
in forested and chaparral
habitat. Genetic analysis
indicates that the species is distinct from other Streptanthus and is most closely related to Streptanthus morrisonii
, which it resembles. It is a hairless annual herb producing an erect branching or unbranched stem 2 to 20 centimeters tall. The ephemeral basal leaves have thick, fleshy leaves which are green and unmottled on top and purple on the undersides. Leaves higher on the stem are linear to lance-shaped and lack petioles
. Flowers occur at intervals along the upper stem. Each flower has an urn-shaped calyx of sepal
s which is solid green with no purple or yellowish tinge. The petals emerging from the tip are white without darker veining. The fruit is a flattened straight silique
3 to 5 centimeters long containing orange seeds.
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 early jewelflower. It was first observed in the 1970s but not actually described to science until 2005. It is endemic to Lake County, California
Lake County, California
Lake County is a county located in the north central portion of the U.S. state of California, north of the San Francisco Bay Area. It takes its name from Clear Lake, the dominant geographic feature in the county and the largest natural lake wholly within California...
, where it is known from a single occurrence at Three Peaks near the Napa County
Napa County, California
Napa County is a county located north of the San Francisco Bay Area in the U.S. state of California. It is coterminous with the Napa, California, Metropolitan Statistical Area. As of 2010 the population is 136,484. The county seat is Napa....
line. It is apparently limited to serpentine outcrops
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....
in forested and 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...
habitat. Genetic analysis
Genetic analysis
Genetic analysis can be used generally to describe methods both used in and resulting from the sciences of genetics and molecular biology, or to applications resulting from this research....
indicates that the species is distinct from other Streptanthus and is most closely related to Streptanthus morrisonii
Streptanthus morrisonii
Streptanthus morrisonii is an uncommon species of flowering plant in the mustard family known by the common name Morrison's jewelflower. It is endemic to California, where it is known from the North and Central Coast Ranges. It is limited to serpentine soils in chaparral and forest habitat. It is...
, which it resembles. It is a hairless annual herb producing an erect branching or unbranched stem 2 to 20 centimeters tall. The ephemeral basal leaves have thick, fleshy leaves which are green and unmottled on top and purple on the undersides. Leaves higher on the stem are linear to lance-shaped and lack petioles
Petiole (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...
. Flowers occur at intervals along the upper stem. Each flower has an urn-shaped calyx of 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 which is solid green with no purple or yellowish tinge. The petals emerging from the tip are white without darker veining. The fruit is a flattened straight 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...
3 to 5 centimeters long containing orange seeds.