Common Sunflower

Sun1.bmp (1941322 bytes)

Cotyledons.  Key characteristics: common sunflower cotyledons are much shorter and spatula-shaped (left) compared to the longer and nearly linear-shaped cotyledons of common cocklebur (right).

Sun2.bmp (1620414 bytes)

Seedling.  Key characteristics: first true leaves are opposite and more longer than narrow; three prominent veins become apparent.

Sun4.bmp (2506194 bytes)

Foliage.  Key characteristics: as the plant develops, leaves become heart-shaped and contain three major veins.

   sunflower.jpg (1195327 bytes)

Flower and infested corn crop.

  

Seed.  Seed are covered with black, gray and brown hairs imparting a mottled appearance.  They are tooth-shaped and range in length from 5.0 to 8.0 mm. 

Life cycle: summer annual.