One of the harbingers of fall is the blooming of goldenrods (Solidago spp.). Their bright yellow blooms are quite beautiful and their robust nature makes them standout wherever they occur. The flowers are excellent sources of nectar, and it’s common to see many pollinating insects, such as bees, wasps and butterflies, visiting these flowers.
There are 21 species of goldenrods found in Florida. Most of them bloom in the fall, but a few will bloom earlier. Most are very similar, making it quite difficult for the average person to identify exactly which species they’re looking at.
One of the most common species is the pinebarren goldenrod (Solidago fistulosa). Like most of the goldenrod species, it is a perennial herb. It inhabits dry pinelands, woodlands, and dry or sandy sites. It starts growing in the spring and reaches maturity in the fall. It typically grows to a height of 4 to 6 feet.
The stems are pubescent (covered with short, soft hairs). The leaves are elliptical in shape and range from 2 to 4 inches long and up to an inch wide. They are slightly toothed and are attached directly to the stem without a supporting stalk or petiole. It is common to find the leaves leaning upwards like they are clasping the stem.
Bright yellow flowers are produced in spike clusters on the upper portions of the flower stalks. These clusters vary in length from 2 to 6 inches. They consist of numerous small tubular flower heads that form along one side of the stalk.
Each flower head is actually a composite flower having both ray flowers and disc flowers. The ray flowers are the petals, which surround the disc flowers in the center. The disc flowers are quite small, averaging less than 0.1 inch in diameter. Each disc flower has petals, a pistil and stamens.
Goldenrods can reproduce by two different methods. One is from seeds produced by the flowers. The second is from rhizomes (horizontal underground stems) and suckers (shoots originating from below ground). Some species produce rhizomes slowly and others are more aggressive.
The pinebarren goldenrod produces large numbers of rhizomes and suckers aggressively in all directions. Thus, this species is usually seen in dense patches and is seldom seen as a solitary plant.
Many people associate goldenrods with hay fever. However, the pollen causing this allergic reaction is produced mainly by ragweed, which blooms at the same time. The pollen produced by goldenrods is too heavy and sticky to be blown far from the flowers. Thus, insects provide the necessary pollination.
Would you believe the goldenrod plant contain rubber? The rubber is contained only in the leaves, not the stems or blooms. The typical rubber content is about seven percent. Inventor Thomas Edison experimented with goldenrod to find a substitute for rubber. Henry Ford, with the help of George Washington Carver, eventually devised a way to make a rubber substitute from goldenrod. Unfortunately, the resulting product was quite tacky and had poor tensile properties.
Be sure to take time to walk through your neighborhood and enjoy Florida’s wildflowers. All of the photographs accompanying this article were taken by the author in the Deep Creek neighborhood.