Photo by Sonja Sommerfeld / TPWD

FLORA FACT

Here Comes the Sunflower

You’ve seen these bright, cheery seed dispensers growing tall and thick in late-summer fields across the state. The sunflower’s not only one of the most recognizable blooms in the state, it provides one of our favorite snacks as well.

Technically called the “fruit” of Helianthus annuus, the seed kernels are housed in an inedible black-and-white striped shell (seeds with black shells are used to produce sunflower oil). Of course, humans are not the only species that enjoy this natural snack, high in vitamin E and antioxidants. Birds, rodents and other mammals love to feast on sunflower seeds.

The plant was first domesticated by Native Americans in prehistoric North America, then brought to Europe in the 16th century. Native Americans had multiple uses for sunflowers: bread, medical ointments, dyes and body paints.

The wild version of the plant has a branched stem with many heads; the domesticated kind you might plant in the garden usually possesses one large head, up to 5 inches across. Each large bloom resembles the sun, hence the name. The heavy blooms teeter on hairy stems that can grow as tall as 8 feet.

Sunflowers love the sun and grow best basking in it. A common misconception is that flowering sunflower heads turn and track the sun across the sky. Although immature flower buds exhibit this behavior, the mature flowering heads point in a fixed (and typically easterly) direction throughout the day.

The outer petals of the sunflower are called ray flowers. The flowers in the center of the head are called disk flowers, and mature into the seeds. Those disk flowers are arranged in a Fibonacci spiral, producing the most efficient packing of seeds in that area, according to the math.

The flamboyant flowers also attract butterflies, especially whites and sulphurs in the fall.