Overview
On June 15, 2021, beardless chinchweed (Pectis imberbis) was listed as endangered under the Endangered Species Act of 1973, as amended, with approximately 4,291 hectares designated as critical habitat. The species is known from Cochise, Pima and Santa Cruz counties of southern Arizona, as well as Sonora and Chihuahua, Mexico. We are aware of six extant populations in the United States containing at least 1,116 individuals. In Mexico, none of the six historical populations has been relocated in recent years, but we presume they are extant with small numbers of individuals. Nine populations, and one subpopulation in Arizona, have become extirpated since 1962. In addition to the extirpated populations and subpopulation, we are aware of three United States populations, Ruby Road, Research Ranch and Scotia Canyon, that have been reduced in size since the 1980s and 1990s. Threats from non-native plant invasion and alteration of fire regimes, drought and climate change climate change
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Scientific Name
Identification Numbers
Characteristics
Physical Characteristics
Beardless chinchweed has been found from 1,158 to 1,737 meters in elevation and are typically found in oak woodlands at higher elevations, and desert grasslands and oak savannas at lower elevations. Plants are typically noted to occur on steep, south-facing, sunny to partially shaded hillslopes, with eroding granite or limestone bedrock. These open areas are dominated by native plants and were historically maintained by light disturbance such as precipitation, gravity, animal path erosion, and low-severity fire.
The beardless chinchweed is an erect, many-branched perennial of the sunflower family Asteraceae that can grow to 12 decimeters in height from a woody root. The leaves of beardless chinchweed are without hair and have on their undersides, oval-shaped glands. The leaves are up to 5 centimeters in length and just 2 millimeters in width and are distributed sparsely up the stems. The daisy-like flower heads of beardless chinchweed have yellow ray and disk flowers, that are solitary or in open, flat-topped clusters at the tips of the branches. Additionally, the flowers are also dotted with oil glands. Flowering occurs from August to October, peaking in September, after plants reach a minimum of 50 centimeters in height. Fruits form thereafter and have small, less that 5 millimeter long, spreading awned black dry fruits called achenes.
Habitat
Beardless chinchweed has been found from 1,158 to 1,737 meters in elevation and are typically found in oak woodlands at higher elevations, as well as desert grasslands and oak savannas at lower elevations. Plants are typically noted to occur on steep, south-facing, sunny to partially shaded hillslopes, with eroding granite or limestone bedrock. These open areas are dominated by native plants and were historically maintained by light disturbance such as precipitation, gravity, animal path erosion and low-severity fire.
Ecosystem with large, flat areas of grasses.
Life Cycle
Beardless chinchweed flowering occurs from August to October, with up to 55 flowers per stem produced. Beardless chinchweed is pollinated by many insect species including bees, flies and butterflies. In propagation trials, it was found that beardless chinchweed have good germination rates, but high seedling mortality.
Beardless chinchweed is a weak competitor of native and non-native understory, and competition from nearby plants has been shown to reduce both flower and seed production. Also sensitive to animals eating flowers, beardless chinchweed respond by reducing seed production. Beardless chinchweed require soil moisture for seed germination, growth and reproduction.
Geography
The current range of beardless chinchweed lies within Cochise, Pima and Santa Cruz of southeastern Arizona and northern Sonora and Chihuahua Mexico.
Timeline
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