Overview
The Kearney's blue-star (Amsonia kearneyana) was listed as endangered without designated critical habitat on January 19, 1989, under the Endangered Species Act of 1973, as amended. In the United States, the taxon occurs in southern Arizona in the Baboquivari Mountains on lands administered by the Tohono O’odham Nation, the Arizona State Land Department, the Bureau of Land Management and the U.S. Fish and Wildlife Service. It may also occur in portions of Sonora, Mexico, where there is one reference to the species occurrence, but this has not been verified. In Arizona, the distribution of Kearney's blue-star is limited to one naturally occurring site, as well as one site where the species has been introduced. The naturally occurring plants are separated into eight subsites. As of 2021, biologists are aware of approximately 342 individuals in both natural and introduced sites, as well as some seed and plants at various botanical institutions. Comparing recent and historical survey efforts of Kearney's blue-star at subsites to which U.S. Fish and Wildlife Service biologists had access, the number of individuals has declined by about 56 percent over the past three decades. Threats from drought and climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.
Learn more about climate change , non-native plant invasion and altered wildfire regime, predation, poorly managed livestock grazing, border issues and others continue.
Scientific Name
Identification Numbers
Characteristics
Life Cycle
The species is capable of reproducing both through seed, sexually, and vegetatively asexually, meaning through roots. Sexual reproduction of this species requires pollinators. It is unknown if the species is able to self-pollinate and produce viable seed. This species exhibits limited recruitment through sexual reproduction.
Seed may persist for long periods of time, at least under artificial conditions. However, water is required for both dispersal and germination, thus reductions in precipitation in recent decades may be the limiting factor in sexual reproduction in this species. Also, the reduction in shade from overstory tree removal due to high severity fire and drought in recent decades may impact successful germination.
The lifespan of the species is unknown, however, individuals at the introduction site have been documented to persist a minimum of 30 years and therefore the lifespan of Kearney’s blue-star may be many decades.
Physical Characteristics
Kearney’s blue-star is a perennial plant in the dogbane family Apocynaceae. The species is a subshrub with a thickened woody root. The hairy stems rarely branch and are up to 90 centimeters tall. Mature plants are nearly as wide as they are tall, and a mature adult may have more than 50 stems. The lower leaves are 1.1 to 1.7 centimeter broad, with the upper leaves 3 to 8 millimeters broad; all are bright green with soft hair. Leaves turn yellow in the fall, making the plants easy to recognize at that time of year. From late April to early May, the plant has large white tubular flowers (corolla tube 1.2 to 1.5 centimeters), tinged with blue at the base form at the end of a stem, which also make plants easy to recognize. The dry fruits develop from June through August and are born singly, or in pairs, at the end of stems and extending above the leaves. This also makes the plant easy to recognize when fruiting. Seeds are cylindrical, corky, for water transport, and large, spanning 8 to 11, by 3 to 4 millimeters.
Habitat
Kearney’s blue-star habitat lies at the lower elevation transition of the Madrean Pine-Oak Woodland and the Semi-Desert Grassland at elevations from 1,095 to 1,830 meters. Within this habitat, the species occurs in both open woodland on unconsolidated slopes of more than 20 degrees, and some plants may also be found within canyon bottoms in full sun to partial shade. The Baboquivari Mountains are a granitic outcrop containing a mixture of species from four distinct floras, making this a very diverse region floristically.
Ecosystem with large, flat areas of grasses.
Land covered by evergreen trees in cool, northern latitudes. Also called taiga.
Geography
The Kearney’s blue star(Amsonia kearneyana) was listed as endangered without designated critical habitat on January 19, 1989, under the Endangered Species Act of 1973, as amended. In the United States, the taxon occurs in southern Arizona in the Baboquivari Mountains on lands administered by the Tohono O’odham Nation, the Arizona State Land Department, the Bureau of Land Management and the U.S. Fish and Wildlife Service. It may also occur in portions of Sonora, Mexico, where there is one reference to the species occurrence, but this has not been verified. In Arizona, the distribution of Kearney’s bluestar is limited to one naturally occurring site, as well as one site where the species has been introduced. The naturally occurring plants are separated into eight subsites. As of 2021, biologists are aware of approximately 342 individuals in both natural and introduced sites, as well as some seed and plants at various botanical institutions. Comparing recent and historical survey efforts of Kearney’s bluestar at subsites to which U.S. Fish and Wildlife Service biologists had access, the number of individuals has declined by about 56 percent over the past three decades.Threats from drought and climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.
Learn more about climate change , non-native plant invasion and altered wildfire regime, predation, poorly managed livestock grazing, border issues and others continue.
Kearney’s blue-star is a narrow endemic species known from a single mountain range, the Baboquivari Mountains, in Pima County of southern Arizona. At the time of listing, Kearney’s blue-star was only known from a single location in the riparian riparian
Definition of riparian habitat or riparian areas.
Learn more about riparian area of South Canyon in the Baboquivari Mountains on lands administered by the Tohono O’odham Nation. From 1988 to 1992, Kearney’s blue-star was established at a second location by outplanting potted plants propagated from South Canyon seed collection. These plants were put into lower Brown Canyon on private land that was later sold and is currently owned and administered by Buenos Aires National Wildlife Refuge. Since the early 1990s, discovery of new plants on lands administered by the Bureau of Land Management and the Arizona State Land Department has increased the known spatial distribution of the species to include ridges in Brown, Jaguar and Thomas canyons. The naturally occurring groups of plants are all considered to be a single population due to the distance between groups being close enough that larger pollinators could visit plants within each group.
Timeline
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