For those with any level of visual acuity, November is the beginning of an overwhelmingly colorful season. Holiday lights, decorations and merchandising efforts all vie to use the most conspicuous and unavoidable selections of shades, many of which cannot be found in nature.
Fortunately, panhandle Florida has many wondrous colors in the leaves of plants and trees which indicate this season at its best. The tones and shades identify both the plant species and the season’s progression.
While there is still plenty of green being produced by pines and palms, the deciduous plants are displaying reds, yellows, purples and browns. Deciduous plants are those which lose their leaves in winter.
Leaves are green because of the chemical pigment chlorophyll, which is plentiful in summer and the dominant compound. This substance dictates the appearance of the leaf during the growing season, but the foliage’s chemistry is far more complex.
The local leaves are putting on a massive show of colors, shades and shapes which occurs annually late in the year and into the holiday season.
Chlorophyll is critical to a plant’s health and growth during the warmer months. It is the chemical catalyst which converts energy from the sun and nutrients into sugars which the plant or tree uses.
Trees and plants produce and utilize chlorophyll throughout the growing season. The robust green coloration is a sign it is healthy and functioning to its fullest capacity.
As summer passes into fall, the cooler temperatures and waning hours of light each day cause plants to constrict their veins and lower the availability of chlorophyll. The plants’ vascular systems, which carry fluids into and out of the leaves, are gradually closed off by a membrane layer at the base of each leaf.
As the seasonal transition progresses, leaf veins will remain green as the other leaf tissues change color. The color and intensity depend on the species of tree or plant.
Carotenoids, which reveal their presence by orange and yellow hues, appear gradually. Hickories and pecans, which are in the Carya genus, have distinctive yellow leaves.
The reds and purples come from another pigment group called anthocyanins which reside in the cells. This chemical compound develops in the leaves’ sap.
These pigments are not present in the leaf during much of the growing season, but they are rapidly produced in August and September. The amount and intensity of the reds and purples in leaves depends on a combination of environmental factors.
The breakdown of sugars, the intensity and duration of sunlight and the level at which phosphate declines in the leaf combine to produce a seemingly infinite number of shade and hue possibilities.
The brightest colorations commonly occur when the fall days are bright and cool, and the nights are cold but not below freezing. Sweet gums, Florida maples and dogwoods all have red to maroon range leaves.
Both creeper and poison ivy are bright cherry red during the waning days of autumn. Sometimes with the loss of leaves, it is difficult to tell the two species apart.
Unfortunately for anyone who physically contacts poison ivy leaves, red or green, they prove to be equally itchy. While the season may change the color, the result is just as uncomfortable.
With 2021 soon passing into the history books, the polychromatic leaves and decorations will mostly come down. Luckily, only the holiday adornments must be packed away until late next year.
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