Astragalus agnicidus
Encyclopedia
Astragalus agnicidus is a rare species of milkvetch
known by the common name Humboldt County milkvetch. It is endemic to northern California
, where it is known only from two populations in Humboldt County
and one in Mendocino County
.
The plant was undescribed until the 1950s. Until then it was known only from one 8 acres (32,374.9 m²) ranch in Humboldt County, where sheep ranchers
blamed the unnamed species for the deaths of their animals, which may have eaten it. They eradicated the plant from their land, and by the time it was formally described and named in 1957 it was thought to be extinct
. The species name given the plant, agnicidus, means "lamb-killer".
The plant was rediscovered in 1987. A few individuals were found growing in a recently bulldozed clearing, their long-buried seeds having been plowed into favorable conditions for germination
. The plants were brought under the protection of the landowners, the same family that was responsible for its near-extinction and had changed their minds about its value. Two other populations of the plant have since been discovered in areas of the coastal mountains that had been recently logged
; this is an early successional species
which arises in disturbed areas. Too much disturbance of an area can be harmful, however, since it may cause the whole patch of buried seeds to sprout at once, making the population vulnerable to destruction as it lacks backup seed stores.
This milkvetch is a perennial herb which lives 5 to 10 years. The coarse reddish stem is slightly hairy toward the ends, growing 30 to 90 centimeters long. The widely spaced leaves are arranged oppositely along the stem. Each is up to 16 centimeters long and is made up of several pairs of oval-shaped leaflets up to about 2 centimeters long. The inflorescence
is a dense cluster of 10 to 40 white pealike flowers. The plant is self-pollinating
and the flowers are also pollinated by native bumblebees. The fruit is a bent legume capsule 1 to 1.5 centimeters long which dries to a papery texture.
Astragalus
Astragalus is a large genus of about 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae, subfamily Faboideae. The genus is native to temperate regions of the Northern Hemisphere...
known by the common name Humboldt County milkvetch. It is endemic to northern 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 only from two populations in Humboldt County
Humboldt County, California
Humboldt County is a county in the U.S. state of California, located on the far North Coast 200 miles north of San Francisco. According to 2010 Census Data, the county’s population was 134,623...
and one in Mendocino County
Mendocino County, California
Mendocino County is a county located on the north coast of the U.S. state of California, north of the greater San Francisco Bay Area and west of the Central Valley. As of the 2010 census, the population was 87,841, up from 86,265 at the 2000 census...
.
The plant was undescribed until the 1950s. Until then it was known only from one 8 acres (32,374.9 m²) ranch in Humboldt County, where sheep ranchers
Sheep husbandry
Sheep husbandry is a subcategory of animal husbandry specifically dealing with the raising and breeding of domestic sheep. Sheep farming is primarily based on raising lambs for meat, or raising sheep for wool. Sheep may also be raised for milk or to sell to other farmers.-Shelter and...
blamed the unnamed species for the deaths of their animals, which may have eaten it. They eradicated the plant from their land, and by the time it was formally described and named in 1957 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...
. The species name given the plant, agnicidus, means "lamb-killer".
The plant was rediscovered in 1987. A few individuals were found growing in a recently bulldozed clearing, their long-buried seeds having been plowed into favorable conditions for germination
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...
. The plants were brought under the protection of the landowners, the same family that was responsible for its near-extinction and had changed their minds about its value. Two other populations of the plant have since been discovered in areas of the coastal mountains that had been recently logged
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
; this is an early successional species
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
which arises in disturbed areas. Too much disturbance of an area can be harmful, however, since it may cause the whole patch of buried seeds to sprout at once, making the population vulnerable to destruction as it lacks backup seed stores.
This milkvetch is a perennial herb which lives 5 to 10 years. The coarse reddish stem is slightly hairy toward the ends, growing 30 to 90 centimeters long. The widely spaced leaves are arranged oppositely along the stem. Each is up to 16 centimeters long and is made up of several pairs of oval-shaped leaflets up to about 2 centimeters long. 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 dense cluster of 10 to 40 white pealike flowers. The plant is self-pollinating
Self-pollination
Self-pollination is a form of pollination that can occur when a flower has both stamen and a carpel in which the cultivar or species is self fertile and the stamens and the sticky stigma of the carpel contact each other in order to accomplish pollination...
and the flowers are also pollinated by native bumblebees. The fruit is a bent legume capsule 1 to 1.5 centimeters long which dries to a papery texture.