''Chorizanthe valida'' is a rare species of flowering plant in the buckwheat family known by the common name Sonoma spineflower. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

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, Di ...

Marin County, California Marin County is a County (United States), county located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2020 United States Census, 2020 census, the population was 262,231. Its county seat and ...

, where it is known from only one remaining natural population at

Point Reyes National Seashore Point Reyes National Seashore is a park preserve located on the Point Reyes Peninsula in Marin County, California. As a national seashore, it is maintained by the US National Park Service as an important nature preserve. Some existing agricult ...

. It was thought to be

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually 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 ...

until 1980 when the Point Reyes population was discovered. ''Chorizanthe valida'' is a federally listed

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

. This plant is erect in form, reaching up to about 30 centimeters tall. The

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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a cluster of flowers with each flower surrounded by six reddish or gray

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 usually different from foliage leaves. They may be smaller, larger, or of ...

s, each tipped with a straight awn. The awns are bright red when new and age ivory white.Reveal, J. L
''C. valida''.
Taxonomic Treatment of Eriogonoideae (Polygonaceae). They are not hard or hooked in shape like those of many other ''Chorizanthe''.USFWS
''Chorizanthe valida'' Five-year Review.
August 2010. The flower is a few millimeters long and white or pink in color. Chorizanthe valida counting

This rare plant once had a wider distribution; specimens were collected many decades ago in neighboring

Sonoma County Sonoma County () is a county (United States), county located in the U.S. state of California. As of the 2020 United States Census, its population was 488,863. Its county seat and largest city is Santa Rosa, California, Santa Rosa. It is to the n ...

. Today it is limited to Point Reyes where there is one natural population at

Abbotts Lagoon Abbotts Lagoon is a lagoon on the northwestern coast of the Point Reyes National Seashore, southwest of Tomales Point, in California, United States. The inland portion of the lagoon receives freshwater runoff, but the lagoon may be brackish fro ...

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 The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

system, can bear only

drought-tolerant plants Drought tolerance is the ability to which a plant maintains its biomass production during arid or drought conditions. Some plants are naturally adapted to dry conditions'','' surviving with protection mechanisms such as desiccation tolerance, detox ...

because it cannot retain much water. Research suggests that areas with

grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other ...

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...

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.The Nature Conservancy
/ref> 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 Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...

dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing da ...

, and

horseback riding Equestrianism (from Latin , , , 'horseman', 'horse'), commonly known as horse riding (Commonwealth English) or horseback riding (American English), includes the disciplines of riding, driving, and vaulting. This broad description includes the ...

activity. Threats that do remain include damage by

hikers Hiking is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century.AMATO, JOSEPH A. "Mind over Foot: Romantic Walking and Rambling." In ''On Foot: A Histor ...

and

off-road vehicle An off-road vehicle, sometimes referred to as an overland or adventure 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 dee ...

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 A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire ...

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

could drive it to extinction.Coppoletta, M. and B. Moritsch
Restoring the abundance of the endangered Sonoma spineflower.
Natural Resource Year in Review 2000. National Park Service.

References

External links

Jepson Manual Treatment: ''Chorizanthe valida''USDA Plants Profile: ''Chorizanthe valida''Flora of North America: ''Chorizanthe valida''''Chorizanthe valida'' Photo gallery

External links

Calflora Database: ''Chorizanthe valida'' (Sonoma spineflower) Jepson eFlora (TJM2) treatment of ''Chorizanthe valida'' UC Photos gallery: ''Chorizanthe valida''
{{authority control valida Endemic flora of California Natural history of the California chaparral and woodlands Natural history of Marin County, California Point Reyes National Seashore West Marin Plants described in 1877 Taxa named by Sereno Watson Critically endangered flora of California Endemic flora of the San Francisco Bay Area

References

External links

Further reading

External links