This week’s column comes from the sunny and warm shores of Sanibel Island Florida. I unfortunately had to come to this location because I am working on a new field guide about the trees of Florida. Oh poor me.
All things consider, the trees found in Florida are an intriguing mix of eastern deciduous forest trees which are found all across eastern US, such as maples, oaks and elms. But Florida also has tropical and sub-tropical trees along with palms found no where else in the US. An interesting mix of trees indeed. I, however, am here for the topical trees and in particular the palms.
Palm trees have long been associated with Florida’s sunny beaches. It’s not hard to envision swaying palm trees on a sandy beach or palm lined boulevards. But has Florida always been one of the palm capitals of North America? The answer is yes and no.
World wide there are as many as 3,000 species of palm tree with only a handful that are native to the United States, and most are restricted to the warmer regions of southern Florida and California.
There are only eight species of palm native to Florida with another three species (total of 11) that have escaped cultivation and are now naturalized in the state. (Naturalized means the plant is now surviving and reproducing on its own in the wild without the aid of people.) All of these palms are found in the southern half of the state where freezing temperatures are not as much a threat.
It should be noted that there are about 25 species of palm that are grown and sold in nurseries for commercial use in the state. Most of these cultivated species come from all across the tropical parts of the world such as Cuba.
Back in 1953, the state legislature voted to designate the Sabal Palm (Sabal palmetto) as the official state tree. The Sabal Palm can be found just about everywhere in the southern half of the state.
Palms are a very unique tree. They are considered phylogenetically more advanced than Pines, and other evergreen trees and they exhibit a very different appearance than other deciduous trees. Let’s talk a look at some of those differences.
The trunk of a palm tree is not divided into bark and wood as in other trees. Instead, they have only an outer shell and an inner cylinder, both of which are composed to living tissue. In other trees only the thin lining just under the bark is living with the “wood” center being dead. Also the trunk grows from the center out increasing the girth of the tree without shedding their outer layer as in other trees.
Another major difference between palms and other trees is their unbranching trunk. Palm trees grow upward from a single terminal bud with a collection of leaves found in the end or top of the tree. As the tree grows the lowest leaves are replaced by new leaves erupting from the top center of the tree. The older lower leaves will dry and turn brown before falling off. Some species of palm retain their old brown leaves giving the tree the appearance of wearing a brown grass skirt.
All palm trees can be divided into two major groups based on the type of leaf. The first group has palmate or fan-shaped leaves. These leaves are characterized by a leaf structure in which all of the leaf segments arise from a single point in the center of the leaf. Similar to the fingers on your hand, all of which originate from a single point, your palm. The second group is pinnate leaves. These kinds of leaves are characterized by leaves with a row of narrow leaflets (smaller leaves) arising from each side of a central stalk, similar in design to a feather.
So there you have it, the palms of Florida in a coconut shell, if you will. The next time you visit the wonderful state of Florida be sure to take a moment and admire the palms. Until next time…