By Steve Roark
Volunteer, Cumberland Gap National Park

When it comes to wildflowers that show up in August and September, two things stand out: yellow is by far the dominant color you’ll see, and many of the flowers have a complex flower structure termed a composite, made up of many flowers. You have to look close to actually see what’s going on here, so let me dive in.
These multi-flowered flowers are all in a family of plants called the Composite Family, also called Asteraceae. When you look at a daisy or sunflower, you are looking at a composite, where the flower you see is made up of many small flowers called florets. From a distance a sunflower looks to be a single flower with a central round disc and largeish petals radiating off it. This type of flower is in fact referred to as a disc flower, like Black Eyed Susan, Oxeye Daisy, etc. What you see is deceiving and is not a single flower. The disc if you look closely is made up of many tiny non-showy flowers called florets that are the true flowers that have the sex organs capable of being pollinated and producing seeds. What look like petals around the floret disc are not true petals, but each is an extremely modified flower called a ray. Weird huh?
Besides the disc and ray flower type structure, there are two other flower forms in the Composite family of plants. Some flowers are composed of only ray flowers with no disc, a good example being a dandelion and chicory. Still another flower structure has all disc flowers with no ray flowers, such as thistle and burdock.
Composite flowers are readily found in our area this time of year, some examples include chicory, dandelion, chrysanthemum, yarrow, coreopsis, sunflower, dahlia, zinnia, goldenrod, fleabane, aster, sneezeweed, lettuce, thistle, ironweed, and Black-eyed Susan.
The composite flower structure is apparently a good design, as there are over 23,000 species of plants that use it and can be found on every continent except Antarctica. Some are considered good guys like the many horticultural flowers available for beautifying your garden, and sunflowers that produce a cooking oil and edible seeds. Others are considered a weedy problem like dandelion and thistle. Still others are purported to have medicinal value such as yarrow and boneset. Whatever you think of them, they are worth a closer look when out hiking.