Amsonia kearneyana
Encyclopedia
Amsonia kearneyana is a rare species of flowering plant in the dogbane family
known by the common name Kearney's bluestar. It is native to Arizona
, where there is only one native population in the Baboquivari Mountains
of Pima County
. There may also be a population just south of the border in Sonora, Mexico. The plant was federally listed as an endangered species
in 1989. At that time the global population of the plant was made up of eight individuals in a riparian canyon
. Since that time the plant has been manually propagated in an attempt to increase its numbers. Threats to the tiny native population include habitat destruction from livestock
activity and flash flood
s in the river canyon. Many of the plants cannot reproduce because their seeds are sterile and nonviable, but this is probably due to insect
predation
on the seeds as they develop.
This is a perennial herb growing from a thick root in rocky, cobbly alluvial
soils. It produces up to 50 hairy stems reaching up to 90 centimeters in height, forming a hemispherical clump which may be nearly 2 meters across. The lance-shaped leaves are up to 10 centimeters long and 1 or 2 centimeters wide. The inflorescence
bears clusters of white flowers each 1 or 2 centimeters long. The corolla is tubular opening into a flat face with short, rounded lobes. The fruit is a follicle
which may be 10 centimeters in maximum length. It contains relatively large seeds which measure about a centimeter long and half a centimeter wide.
The land in the area is stewarded by the Bureau of Land Management
, Buenos Aires National Wildlife Refuge
, and the Tohono O'odham Nation
. The plant occurs at 1095–1160 m (3,592.5–3,805.8 ) elevation
. Its habitat is made up of riparian vegetation surrounded by Sonoran Desert
scrub, in a transition between Madrean
woodlands and chaparral
.
Apocynaceae
The Apocynaceae or dogbane family is a family of flowering plants that includes trees, shrubs, herbs, and lianas.Many species are tall trees found in tropical rainforests, and most are from the tropics and subtropics, but some grow in tropical dry, xeric environments. There are also perennial herbs...
known by the common name Kearney's bluestar. It is native to Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, where there is only one native population in the Baboquivari Mountains
Baboquivari Peak Wilderness
The Baboquivari Peak Wilderness is a wilderness area in the U.S. state of Arizona. It is located in the Baboquivari Mountain Range southwest of Tucson, Arizona. It is administered by the Bureau of Land Management. The United States Congress designated the Baboquivari Peak Wilderness in 1990. It...
of Pima County
Pima County, Arizona
-2010:Whereas according to the 2010 U.S. Census Bureau:*74.3% White*3.5% Black*3.3% Native American*2.6% Asian*0.2% Native Hawaiian or Pacific Islander*3.7% Two or more races*12.4% Other races*34.6% Hispanic or Latino -2000:...
. There may also be a population just south of the border in Sonora, Mexico. The plant was federally listed as an 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...
in 1989. At that time the global population of the plant was made up of eight individuals in a riparian canyon
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
. Since that time the plant has been manually propagated in an attempt to increase its numbers. Threats to the tiny native population include habitat destruction from livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
activity and flash flood
Flash flood
A flash flood is a rapid flooding of geomorphic low-lying areas—washes, rivers, dry lakes and basins. It may be caused by heavy rain associated with a storm, hurricane, or tropical storm or meltwater from ice or snow flowing over ice sheets or snowfields...
s in the river canyon. Many of the plants cannot reproduce because their seeds are sterile and nonviable, but this is probably due to insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
on the seeds as they develop.
This is a perennial herb growing from a thick root in rocky, cobbly alluvial
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
soils. It produces up to 50 hairy stems reaching up to 90 centimeters in height, forming a hemispherical clump which may be nearly 2 meters across. The lance-shaped leaves are up to 10 centimeters long and 1 or 2 centimeters wide. 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...
bears clusters of white flowers each 1 or 2 centimeters long. The corolla is tubular opening into a flat face with short, rounded lobes. The fruit is a follicle
Follicle (fruit)
In botany, a follicle is a dry unilocular many-seeded fruit formed from one carpel and dehiscing by the ventral suture in order to release seeds, such as in larkspur, magnolia, banksia, peony and milkweed....
which may be 10 centimeters in maximum length. It contains relatively large seeds which measure about a centimeter long and half a centimeter wide.
The land in the area is stewarded by the Bureau of Land Management
Bureau of Land Management
The Bureau of Land Management is an agency within the United States Department of the Interior which administers America's public lands, totaling approximately , or one-eighth of the landmass of the country. The BLM also manages of subsurface mineral estate underlying federal, state and private...
, Buenos Aires National Wildlife Refuge
Buenos Aires National Wildlife Refuge
Buenos Aires National Wildlife Refuge provides of habitat for threatened and endangered plants and animals. The refuge was established in 1985.-Natural history:...
, and the Tohono O'odham Nation
Tohono O'odham
The Tohono O'odham are a group of Native American people who reside primarily in the Sonoran Desert of the southeastern Arizona and northwest Mexico...
. The plant occurs at 1095–1160 m (3,592.5–3,805.8 ) elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....
. Its habitat is made up of riparian vegetation surrounded by Sonoran Desert
Sonoran Desert
The Sonoran Desert is a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the northwest Mexican states of Sonora, Baja California, and Baja California Sur. It is one of the largest and hottest...
scrub, in a transition between Madrean
Madrean Region
The Madrean Region is a floristic region within the Holarctic Kingdom in North America, as delineated by Armen Takhtajan and Robert F. Thorne...
woodlands and chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
.