''Chorizanthe howellii'' is a species of flowering plant in the

buckwheat family The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—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 ...

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 els ...

to coastal

Mendocino County, California Mendocino County (; ''Mendocino'', Spanish for "of Mendoza) is a county located on the North Coast of the U.S. state of California. As of the 2020 census, the population was 91,601. The county seat is Ukiah. Mendocino County consists wholly ...

, 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 C ...

. 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. 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 ...

is a cluster of flowers, each surrounded by a starlike array of six spreading white bracts 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 d ...

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''. It is native to the coastlines of Europe and North Af ...

''. 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