About Helenium microcephalum DC.
Helenium microcephalum, commonly called smallhead sneezeweed, is a North American plant in the Asteraceae family. It grows in the southwestern and south-central United States as well as northern Mexico. This species is an annual herb that reaches up to 120 cm (4 feet) tall, with wing-like ridges running along the sides of its stems. Its leaves are narrow and elliptical in shape. A single plant can produce 300 or more small flower heads, which are either spherical or egg-shaped and generally no more than 12 mm (half an inch) in diameter. Each flower head holds 400 or more tiny disc flowers, measuring 1.2–2.4 mm (0.047–0.094 inches) across. These disc flowers are yellow or yellow-green near the base, and brown or red at the tip. Each flower head also has 7 to 13 ray flowers, which can be either red or yellow. There are two accepted varieties: Helenium microcephalum var. microcephalum, found in Arizona, New Mexico, Oklahoma, Colorado, Texas, and the Mexican states of Coahuila, Nuevo León, and Tamaulipas; and Helenium microcephalum var. ooclinium (A. Gray) Bierner, found in Texas and the Mexican states of Coahuila, Chihuahua, Nuevo León, Durango, and San Luis Potosí.
