Calystegia stebbinsii
Encyclopedia
Calystegia stebbinsii is a rare species of morning glory
known by the common name Stebbins' false bindweed. It is endemic to the Sierra Nevada foothills of California
, where it is known from only two spots in El Dorado
and Nevada Counties
. It grows in unique habitat in chaparral
on gabbro
soils. It is a federally listed endangered species
.
The inflorescence
bears flowers atop long peduncles
, each flower about 3 centimeters wide and white or cream-yellow in color, sometimes tinted with pink. They are pollinated
by bee
s and other insects. Like many other chaparral plants, this species has seeds which are stimulated to germinate
by exposure to wildfire
. It also reproduces via rhizome
.
in 1970 outside of Placerville, California
. The species was described to science and named for him in 1974. The plant is known from only two locations, each containing a scattering of occurrences. Both locations are on the Pine Hill intrusion
, a section of gabbro-based rock that oozed as magma
into the surrounding rock and then solidified there, eventually becoming exposed as the softer rock around them eroded
away. This gabbro intrusion yields red-colored soil that is rich in heavy metals, and some plants are adapted
to this kind of substrate. C. stebbinsii grows on the gabbro soil as well as the similar serpentine soil
that can also be found in the intrusion. Other species are completely limited to the gabbro sections. The Pine Hill Ecological Reserve
was established to protect these unique and often rare plant species.
At the time it was placed on the endangered species list, at least one third of the known occurrences of the plant had been destroyed, mostly by development of its habitat. Most of the sites that still existed were in danger of destruction. With destruction and fragmentation
of the habitat come associated activity such as road
construction, trash dumping, off-road vehicle
use, and herbicide
s.
The plant does not tolerate shade, and when the brush around it grows too high and shades it out, it does not survive. This suggests it requires disturbance, such as wildfire
, to clear the overgrowth. Fire suppression is detrimental. Protected and managed areas of the habitat undergo controlled burn
s.
Morning glory
Morning glory is a common name for over 1,000 species of flowering plants in the family Convolvulaceae, whose current taxonomy and systematics is in flux...
known by the common name Stebbins' false bindweed. It is endemic to the Sierra Nevada foothills of 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 only two spots in El Dorado
El Dorado County, California
El Dorado County is a county located in the historic Gold Country in the Sierra Nevada Mountains and foothills of the U.S. state of California. The 2010 population was 181,058. The El Dorado county seat is in Placerville....
and Nevada Counties
Nevada County, California
Nevada County is a county located in the Sierra Nevada of California, in the Mother Lode country. As of 2010 its population was 98,764. The county seat is Nevada City.-History:Nevada County was created in 1851 from parts of Yuba County....
. It grows in unique habitat 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...
on gabbro
Gabbro
Gabbro refers to a large group of dark, coarse-grained, intrusive mafic igneous rocks chemically equivalent to basalt. The rocks are plutonic, formed when molten magma is trapped beneath the Earth's surface and cools into a crystalline mass....
soils. It is a federally listed endangered species
Endangered species
An 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...
.
Description
Calystegia stebbinsii is a perennial herb producing climbing, white haired, vine-like stems approaching a meter in maximum length. The leaves are up to about 5 centimeters long and palmate in shape with 7 to 9 long, narrow lobes; the distinctive shape of the leaves make the plant easy to identify among the morning glories native to the region.The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
bears flowers atop long peduncles
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
, each flower about 3 centimeters wide and white or cream-yellow in color, sometimes tinted with pink. They are pollinated
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
by bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s and other insects. Like many other chaparral plants, this species has seeds which are stimulated to germinate
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
by exposure to wildfire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
. It also reproduces via rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
.
Conservation
The plant's type specimen was collected by G. Ledyard StebbinsG. Ledyard Stebbins
George Ledyard Stebbins, Jr. was an American botanist and geneticist who is widely regarded as one of the leading evolutionary biologists of the 20th century. Stebbins received his Ph.D. in botany from Harvard University in 1931. He went on to the University of California, Berkeley, where his work...
in 1970 outside of Placerville, California
Placerville, California
Placerville is the county seat of El Dorado County, California. The population was 10,389 at the 2010 census, up from 9,610 at the 2000 census. It is part of the Sacramento–Arden-Arcade–Roseville Metropolitan Statistical Area.-Geography:...
. The species was described to science and named for him in 1974. The plant is known from only two locations, each containing a scattering of occurrences. Both locations are on the Pine Hill intrusion
Intrusion
An intrusion is liquid rock that forms under Earth's surface. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the rock slowly...
, a section of gabbro-based rock that oozed as magma
Magma
Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...
into the surrounding rock and then solidified there, eventually becoming exposed as the softer rock around them eroded
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
away. This gabbro intrusion yields red-colored soil that is rich in heavy metals, and some plants are adapted
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
to this kind of substrate. C. stebbinsii grows on the gabbro soil as well as the similar 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....
that can also be found in the intrusion. Other species are completely limited to the gabbro sections. The Pine Hill Ecological Reserve
Pine Hill Ecological Reserve
Pine Hill Ecological Reserve is a nature reserve of located due east of Folsom Lake, in El Dorado County, California. The reserve was established in 1979, and is managed by the California Department of Fish and Game....
was established to protect these unique and often rare plant species.
At the time it was placed on the endangered species list, at least one third of the known occurrences of the plant had been destroyed, mostly by development of its habitat. Most of the sites that still existed were in danger of destruction. With destruction and fragmentation
Habitat fragmentation
Habitat fragmentation as the name implies, describes the emergence of discontinuities in an organism's preferred environment , causing population fragmentation...
of the habitat come associated activity such as road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
construction, trash dumping, off-road vehicle
Off-road vehicle
An off-road vehicle is considered to be any type of vehicle which is capable of driving on and off paved or gravel surface. It is generally characterized by having large tires with deep, open treads, a flexible suspension, or even caterpillar tracks...
use, and herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
s.
The plant does not tolerate shade, and when the brush around it grows too high and shades it out, it does not survive. This suggests it requires disturbance, such as wildfire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
, to clear the overgrowth. Fire suppression is detrimental. Protected and managed areas of the habitat undergo controlled burn
Controlled burn
Controlled or prescribed burning, also known as hazard reduction burning or Swailing is a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement. Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for...
s.