Astranthium, commonly known as Western-daisy, is a small North American genus of herbaceous flowering plants in the daisy family Asteraceae (order Asterales). The genus is native to the United States and Mexico, with individual species distributed across the Southern Plains, the Cumberland Plateau, the Ohio and Tennessee valleys, and parts of northern and central Mexico.
Members of the genus bear the characteristic composite flower heads typical of Asteraceae, with ray florets surrounding a central disc — giving them the daisy-like appearance that lends the genus its common name. Species range from low-growing annuals to perennials found in open grasslands, rocky slopes, and disturbed habitats across their range.
The genus comprises roughly a dozen described species. Among the best-known are Astranthium integrifolium, found across the southeastern United States from Tennessee and Kentucky south to Alabama and Georgia; Astranthium ciliatum, widespread across the Southern Plains from Texas north to Missouri; and Astranthium robustum, restricted to western Texas. Several species are endemic to Mexico, including taxa confined to Oaxaca, Chiapas, Nuevo León, and Jalisco.
Distribution
Astranthium is native to the United States and Mexico. U.S. species occur primarily across the Southern Plains (Texas, Oklahoma, Arkansas, Kansas, Missouri) and the Cumberland Plateau and Ohio/Tennessee Valley region (Tennessee, Kentucky, Mississippi, Alabama, Georgia, West Virginia). Mexican species are distributed across Oaxaca, Chiapas, Hidalgo, Veracruz, Jalisco, Nuevo León, Durango, Chihuahua, and central Mexico.
Taxonomy Notes
Astranthium is placed in the family Asteraceae, order Asterales. GBIF does not record a formal authorship string for the genus name. The genus is sometimes treated in the tribe Astereae alongside related daisy genera. Species-level taxonomy has been revised by several botanists including Larsen and DeJong, and the species circumscription varies among treatments.
