Zinnia grandiflora is a species of flowering plant in the aster family known by the common names Rocky Mountains zinnia and plains zinnia. It is native to the southwestern and south-central United States (Kansas, Oklahoma, Texas, Colorado, New Mexico, Arizona) and northern Mexico (Chihuahua, Coahuila, Sonora, Tamaulipas, Nuevo León, Zacatecas).Zinnia grandiflora is a small flat-topped or rounded subshrub growing up to 22 centimeters (8.8 inches) tall with many slender, branching stems. The oppositely ...