''Chorizanthe howellii'' is a species of flowering plant in the buckwheat family known by the common names Mendocino spineflower and Howell's 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 ...

to coastal

Mendocino County, California Mendocino County (; ''Mendocino'', Spanish language, Spanish for "of Antonio de Mendoza, Mendoza) is a County (United States), county located on the North Coast (California), North Coast of the U.S. state of California. As of the 2020 United Sta ...

, where it is known only from the sand dunes and coastal scrub near

Fort Bragg Fort Bragg is a military installation of the United States Army in North Carolina, and is one of the largest military installations in the world by population, with around 54,000 military personnel. The military reservation is located within Cum ...

. It is estimated that 95% of the remaining individuals of this plant are part of a single population growing at

MacKerricher State Park MacKerricher State Park is a state park in California in the United States. It is located north of Fort Bragg in Mendocino County. It covers of coastline and contains several types of coastal habitat, including beaches, dunes, headlands, coves, ...

.US Fish & Wildlife Service, Arcata
Howell's Spineflower: Five-year Review.
September, 2007. It 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 is a decumbent or spreading species, growing hairy stems along the ground up to about 10 centimeters long. 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, each surrounded by a starlike array of six spreading white

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 tipped with straight brown awns. The flower itself is a few millimeters wide and white to pale pink in color.Flora of North America, ''Chorizanthe howellii''
/ref> Threats to this species have historically included

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 ...

use, trampling by people on foot and horseback, non-native plant species such as the iceplant ''

Carpobrotus edulis ''Carpobrotus edulis'' is a ground-creeping plant with succulent leaves in the genus '' Carpobrotus'', native to South Africa. Its common names include hottentot-fig, sour fig, ice plant or highway ice plant. Description ''Carpobrotus edulis' ...

'' and beachgrass ''

Ammophila arenaria ''Ammophila arenaria'' is a species of grass in the family Poaceae. It is known by the common names marram grass and European beachgrass. It is one of two species of the genus ''Ammophila (Poaceae), Ammophila''. It is native to the coastlines of ...

''. These impacts have been reduced in the state park with a ban on off-road vehicles, limiting foot and horse traffic, and removal of non-native plant species.

References

External links

Jepson Manual Treatment: ''Chorizanthe howellii''The Nature Conservancy''Chorizanthe howellii'' Photo gallery
howellii Endemic flora of California Natural history of the California chaparral and woodlands Natural history of Mendocino County, California Critically endangered flora of California {{Polygonaceae-stub