Asteraceae : Helianthus annuus
Native American Name
Lakota: waȟčá zizí, waȟčá zí tȟáŋka
Helianthus annuus is an annual, erect, coarse, tap-rooted plant with stems that are 0.6-3 m tall and rough-hairy. The lower-most leaves are opposite, but most of the leaves are alternate with a long petiole. The blades are ovate to triangular, 10-40 cm long and 5-20 cm wide, egg-shaped to triangular, with toothed to almost entire margins and 3 primary veins radiating from the base. There are 1- many heads in the inflorescence, with each flower head attached to a long peduncle at the end of a branch, the heads are 7.5-15 cm wide, and the involucre has several series of ovate bracts with a long abruptly tapered tip, that often have short hairs along their edges. The 10-40 ray flowers are yellow, the ligule 2.5+ cm long. The numerous disk flowers are reddish-brown to purple or rarely yellow. The achenes are 3-15 mm long. Common sunflowers bloom from July through September in open sites and disturbed areas throughout South Dakota.