Chorizanthe valida
Encyclopedia
Chorizanthe valida is a rare species of flowering plant in the buckwheat family
known by the common name Sonoma spineflower. It is endemic to West Marin
, Marin County, California
, where it is known from only one remaining natural population at Point Reyes National Seashore
. It was thought to be extinct
until 1980 when the Point Reyes population was discovered.
Chorizanthe valida is a federally listed endangered species
.
This plant is erect in form, reaching up to about 30 centimeters tall. The inflorescence
is a cluster of flowers with each flower surrounded by six reddish or gray bract
s, each tipped with a straight awn. The awns are bright red when new and age ivory white
. They are not hard or hooked in shape like those of many other Chorizanthe. The flower is a few millimeters long and white or pink in color.
This rare plant once had a wider distribution; specimens were collected many decades ago in neighboring Sonoma County
. Today it is limited to Point Reyes where there is one natural population at Abbotts Lagoon
and one that has been reintroduced by humans near Bull Point. The number of individuals is variable.
The local habitat is coastal prairie
on deep, sandy soils. The soil, remnants of a Pleistocene
dune
system, can bear only drought-tolerant plants
because it cannot retain much water.
Research suggests that areas with grazing
cattle
contain a larger number of plants than areas where animals are excluded, but the plants in the exclusion areas are larger and have more flowers. Cattle do not eat the rare plant and may in fact help clear the land of invasive
non-native plants
, such as velvetgrass
(Holcus lanatus). The land around Abbotts Lagoon is a cattle pasture today.
This species occurs within the bounds of a protected National Seashore, so its habitat will not be developed, and it is protected from such activities as mining
, dredging, and horseback riding
activity. Threats that do remain include damage by hikers
and off-road vehicle
s. The overall effects of cattle on the land are not certain; they may actually be a positive force in the life of the rare plant. The plant is limited to two relatively small populations, so any one severe event such as wildfire
or drought
could drive it to extinction.
Polygonaceae
Polygonaceae is a family of flowering plants known informally as the "knotweed family" or "smartweed family"— "buckwheat family" in the United States. The name is based on the genus Polygonum and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name refers...
known by the common name Sonoma spineflower. It is endemic to West Marin
West Marin
West Marin is the largest rural region of Marin County, California.The West Marin Chamber of Commerce includes seven unincorporated communities in its definition of West Marin: Point Reyes Station, Olema, Stinson Beach, Bolinas, Tomales, Dillon Beach, and Inverness...
, 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 from only one remaining natural population at Point Reyes National Seashore
Point Reyes National Seashore
Point Reyes National Seashore is a park preserve located on the Point Reyes Peninsula in Marin County, California, USA. As a national seashore, it is maintained by the US National Park Service as a nationally important nature preserve within which existing agricultural uses are allowed to continue...
. It was thought to be extinct
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
until 1980 when the Point Reyes population was discovered.
Chorizanthe valida 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...
.
This plant is erect in form, reaching up to about 30 centimeters tall. 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...
is a cluster of flowers with each flower surrounded by six reddish or gray bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s, each tipped with a straight awn. The awns are bright red when new and age ivory white
Ivory (color)
Ivory is an off-white color that resembles ivory, the material out of which the teeth and tusks of animals is made. It has a very slight tint of yellow....
. They are not hard or hooked in shape like those of many other Chorizanthe. The flower is a few millimeters long and white or pink in color.
This rare plant once had a wider distribution; specimens were collected many decades ago in neighboring Sonoma County
Sonoma County, California
Sonoma County, located on the northern coast of the U.S. state of California, is the largest and northernmost of the nine San Francisco Bay Area counties. Its population at the 2010 census was 483,878. Its largest city and county seat is Santa Rosa....
. Today it is limited to Point Reyes where there is one natural population at Abbotts Lagoon
Abbotts Lagoon
Abbotts Lagoon is a two-stage lagoon near the western coast of the Point Reyes National Seashore. The upper lagoon is a fresh water impoundment which overflows into a lower brackish level with occasional winter tidal exchange...
and one that has been reintroduced by humans near Bull Point. The number of individuals is variable.
The local habitat is coastal prairie
Coastal prairie
Coastal prairie may refer to either:* The California coastal prairie, a plant community found along the coasts of California and Oregon* The Western Gulf coastal grasslands of Louisiana, Texas, and Tamaulipas...
on deep, sandy soils. The soil, remnants of a Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
dune
Dune
In physical geography, a dune is a hill of sand built by wind. Dunes occur in different forms and sizes, formed by interaction with the wind. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind...
system, can bear only drought-tolerant plants
Xerophyte
A xerophyte or xerophytic organism is a plant which has adapted to survive in an environment that lacks water, such as a desert. Xerophytic plants may have adapted shapes and forms or internal functions that reduce their water loss or store water during long periods of dryness...
because it cannot retain much water.
Research suggests that areas with grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
contain a larger number of plants than areas where animals are excluded, but the plants in the exclusion areas are larger and have more flowers. Cattle do not eat the rare plant and may in fact help clear the land of invasive
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
non-native plants
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
, such as velvetgrass
Yorkshire Fog
Yorkshire Fog or Velvet Grass, Holcus lanatus, is a perennial grass in the Poaceae Family. 'Lanatus' is latin for 'wooly' which describes the plant's hairy texture....
(Holcus lanatus). The land around Abbotts Lagoon is a cattle pasture today.
This species occurs within the bounds of a protected National Seashore, so its habitat will not be developed, and it is protected from such activities as mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
, dredging, and horseback riding
Equestrianism
Equestrianism more often known as riding, horseback riding or horse riding refers to the skill of riding, driving, or vaulting with horses...
activity. Threats that do remain include damage by hikers
Hiking
Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...
and 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...
s. The overall effects of cattle on the land are not certain; they may actually be a positive force in the life of the rare plant. The plant is limited to two relatively small populations, so any one severe event 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...
or drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
could drive it to extinction.
External links
- Jepson Manual Treatment: Chorizanthe valida
- USDA Plants Profile: Chorizanthe valida
- Flora of North America: Chorizanthe valida
- Chorizanthe valida Photo gallery
Further reading
- Rilla, E. and L. Bush. (2009). The changing role of agriculture in Point Reyes National Seashore. University of California Cooperative Extension Marin.