Streptanthus morrisonii
Encyclopedia
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 soil
s in chaparral
and forest habitat. It is considered a species complex
which includes Streptanthus brachiatus
. S. morrisonii is divided into four subspecies and is variable. In general, it is a biennial herb producing a hairless, waxy stem up to 1.2 to 1.5 meters in maximum height, often branching at the tip. The basal leaves have fleshy, lance-shaped blades 3 to 5 centimeters long borne on petioles
. The blades are gray-green on the upper surface and purple or purple-mottled underneath. Leaves higher on the stem are variable in shape and become smaller toward the top of the plant. Flowers occur at intervals along the upper stem. Each has an urn-shaped calyx of keeled sepal
s in shades of yellow-green to purple. The petals emerging from the tip are whitish with purple-brown veining. The fruit is a flattened straight or slightly curved silique
up to 8 centimeters long.
Threats to this species include boron
toxicity from the steam of nearby geothermal power plants.
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 Morrison's 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 from the North and Central Coast Ranges. It is limited to 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 in 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 forest habitat. It is considered a species complex
Species complex
A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...
which includes Streptanthus brachiatus
Streptanthus brachiatus
Streptanthus brachiatus is a species of flowering plant in the mustard family known by the common name Socrates Mine jewelflower. It is endemic to the Inner North Coast Ranges of California north of the San Francisco Bay Area. It can be found in chaparral and woodland habitat, often on serpentine...
. S. morrisonii is divided into four subspecies and is variable. In general, it is a biennial herb producing a hairless, waxy stem up to 1.2 to 1.5 meters in maximum height, often branching at the tip. The basal leaves have fleshy, lance-shaped blades 3 to 5 centimeters long borne on 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...
. The blades are gray-green on the upper surface and purple or purple-mottled underneath. Leaves higher on the stem are variable in shape and become smaller toward the top of the plant. Flowers occur at intervals along the upper stem. Each has an 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 in shades of yellow-green to purple. The petals emerging from the tip are whitish with purple-brown veining. The fruit is a flattened straight or slightly curved 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 8 centimeters long.
Threats to this species include boron
Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
toxicity from the steam of nearby geothermal power plants.