Taking a look at giant sunflowers

By Jim Gilbert

The first wide open giant sunflower blossom was seen in our area on July 25.

Examining a sunflower closely we see it is not a single flower but a whole bouquet. We can see many, hundreds or a thousand plus small flowers packed together in a structure known as a head.

The outside yellow flowers are called the ray flowers, and although flowers normally serve to produce seeds the ray flowers (banner flowers) of the sunflower are sterile and their function is to attract pollinators such as honey bees, wild bees and butterflies. The flowers of the head, called disk flowers are inconspicuous and small but attend to pollination and seed production.

Some people believe that sunflowers twist their stems so their blossoms face the sun all day. Not true. Green plants are phototropic and respond by growing toward the source of light.

Many plants, particularly in early stages of growth bend toward the east in the morning and toward the west in the evening, and the sunflower shows this tendency also. But once the flower head opens, it no longer turns toward the source of light, and the heads of the sunflowers end up facing east the whole day.

The giant sunflower is related to the native annual sunflower, we see blooming now along roadsides and was first cultivated by Native Americans for its edible seeds. In nature the flowers are only a few inches in diameter, but cultivated varieties sometimes exceed 12 inches across (the giants).

There are many varieties of the native annual sunflower. The seeds are used for bird seed and snacks for people, and they are crushed and the oil is extracted for use as salad and cooking oil.

The oil, which is high in polyunsaturates and low in cholesterol, is a basic ingredient in some margarine.

Plant stems have been used as a source of fiber for the manufacture of fabrics and paper. Research continues to find new ways to use the oil and other plant parts. Many of us enjoy the beauty of sunflower blossoms in our gardens or in the wild.

 

What’s happening outdoors now?

Young hummingbirds are beginning to come to sugar water feeders, so we notice an increase in activity. Flocks of Canada geese are flying and honking. House wrens continue to sing. Now that thistle seeds are ripe, American goldfinches are nesting.

Monarch and eastern tiger swallowtail butterflies nectar on blazing-star and purple coneflowers.

 

On Aug. 7 a year ago

We had a low temperature of 62 and a high of 77 degrees under sunny skies. Both common and great ragweeds had begun shedding pollen. Fields of spring wheat looked golden-brown. Mourning doves and northern cardinals were vocal.

 

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