Southern Sugar Maple (Soapberry Family)
Acer saccharum ssp. floridanum (Sapindaceae)
Origin: Eastern U.S. from the Carolinas to Florida
Of the many aspects of “northern living” that recent transplants to Florida miss is the turning of leaf color in fall. While it’s true that most of our oaks stay green year round, and palms only turn yellow if something is quite wrong, there are a few color changes in the Florida landscape. The maples are the most popular choice, Acer rubrum, red maple. A lesser-used species is Acer saccharum, Southern Sugar Maple, a bit more stately of a tree. Usually found in the northern parts of Florida, the Acer saccharum here at Selby takes both the salt of the bay and the heat of our summers in stride, and turns a lovely red every winter.
Why do leaves of some trees change color and fall off, while others stay green and stay put? To put it simply, it’s a matter of light conditions. The tropical “belt” which rings the planet is not affected by shorter or longer days depending on the time of year; daylight stays pretty consistent throughout, and most tropical trees keep their leaves. As you venture further toward the poles, into temperate areas, the tilt of the earth causes long days in “summer” and short days in “winter.” Of course, whether it is currently winter or summer depends on which pole you’re closest to, so trees from these temperate environments must deal with these changes.
During summer, when water is abundant and there is plenty of sunlight, trees produce sugars and oxygen in a process called photosynthesis. The chemical called chlorophyll aids in this process. It is the presence of chlorophyll that makes leaves green. As the days shorten and light becomes scarce, deciduous trees stop photosynthesizing, halting chlorophyll production. At this point, any food the tree needs for the winter is stored in its stems, and the leaves become useless. Before they fall off, we can see pigments like anthocyanins and carotenoids, caused by sugars trapped in the leaf tissues, which are yellow and red. It’s only because of the lack of chlorophyll that their colors become visible. You can see what this looks like right now. Our Acer saccharum ssp. floridanum is planted along the north bank of the Tidal Lagoon. You can’t miss it -- it’s the big red tree next to all the smaller green ones.
Text by David Troxell