Acourtia potosina

Acourtia potosina is a perennial herb or subshrub in the family Asteraceae, belonging to the genus Acourtia, a New World group of composites historically placed in Perezia and related to the tribes Mutisieae and Nassauvieae. The genus Acourtia contains approximately 60 species distributed from the southwestern United States through Mexico and into Central America, with Mexico serving as the primary center of diversity. The epithet 'potosina' denotes an origin in or near the state of San Luis Potosí in north-central Mexico, a region of diverse topography ranging from semi-arid scrublands to cloud forests that supports high plant endemism. Like other Acourtia species, this plant likely produces alternate or opposite leaves with toothed or lobed margins, and erect stems bearing spicate or paniculate inflorescences of small capitula. The capitula contain only bilabiate florets or ligulate florets depending on the subgroup, with a pappus of slender bristles. Flower color varies across the genus from white and pink to lavender or purple. Acourtia species typically inhabit dry slopes, rocky outcrops, scrubby vegetation, and oak-pine woodland margins at low to mid elevations. Several Acourtia species are used in Mexican traditional medicine for treatment of various ailments. The complex terrain and diverse habitats of San Luis Potosí support numerous endemic plant species, and Acourtia potosina contributes to the region's botanical heritage. Pollination in Acourtia is primarily by bees and butterflies attracted to the showy inflorescences.