Resting Under Laurels

Many of the English names that we use for plants reflect the perceptions and memories of early European colonists in the New World. English herbals (texts about medicinal plants) were once held as the summit of botanical knowledge, but were mostly limited to species found in Western Europe and the Mediterranean region; classical Greek and Latin works formed the foundation of the early plant studies, again based on the known world at the time. In some cases, the reference to an Old World plant is completely baseless, as with many West Indian trees with the suffixes -plum, -apple, -date, -myrtle, or -cedar; occasionally the reference reflects a true affinity within a plant family, as in the Lauraceae, or laurel family. "Resting on one's laurels" refers to the lethargy afflicting a person who, having attained great fame, no longer feels any need of further exertion. The phrase derives from the practice of offering wreaths of laurel to outstanding Roman citizens (who, we must imagine, promptly slacked off!) The Mediterranean "laurel" of the wreath is Laurus nobilis the same as the fragrant "bay leaf' used as a seasoning. It is also the genus which lends its name to the family.

The Lauraceae is represented worldwide in the tropics and subtropics, with concentrations in Southeast Asia and tropical America. A few genera range into the temperate zones. Leaves are simple and spirally arranged, although they appear alternate (rarely opposite.) They are often evergreen, leathery, of medium size, and narrowed at the base and tip, an architecture so common that it gave rise to the term "laurel-type" leaf to describe many unrelated tropical plant species which have all evolved similar leaf shapes, so well adapted to rainforest environments. One other feature of the Lauraceae is helpful in identifying this family: most of the plant tissues have ethereal oils which produce aromas ranging from sweet and spicy to pungent. Obviously, the function of such secondary compounds is not meant for our enjoyment, but rather to discourage herbivores. The flowers are small, and in multiples of three. A small but visible characteristic of the flower is that the anthers (which produce pollen) have two or four flaplike valves. The fruit is a one-seeded berry, the base of which often has an enlarged bowl-Eke structure called a cupule, resembling the cup of an acorn.

The largest and most widespread genus of the Lauraceae in Florida is Persea. Redbay (Persea borbonia) can become a large tree with dark furrowed bark; the leaves are often deformed by galls. Florida species of Persea are separated by the types of hairs on the leaf surface. (Based on leaf shape, in a parallel to the coining of the term "laurel-type" leaf, popular usage has applied the term "bay tree" to unrelated plants which may grow together or as discrete communities. "Sweetbay" is Magnolia virginiana in the Magnolia family, and Loblolly Bay is Gordonia lasianthus, in the Tea Family.) The Avocado is Persea americana, a tropical American tree long cultivated for its rich oily flesh. Camphor Tree (Cinnamomum camphora) is an unwelcome exotic pest plant, originating in the Far East.

Central and North Florida are home to Sassafras (Sassafras albidum), a small tree with lobed deciduous leaves, once commonly used as a tea. Two other genera, Litsea and Lindera, are also restricted to the north. Licaria triandra, a tree with a fruit resembling a black acorn, is restricted to few sites in Dade County, and is listed as endangered. Lancewood (Ocotea coriacea, formerly Nectandra coriacea) is found in maritime hammocks from the Keys north to east central Florida. This beautiful small tree could be used more often in ornamental landscapes.

The habit of "Love Vine" (Cassytha filiformis) is in sharp contrast to all the taxa described above. This plant grows as a parasitic vine, absent of leaves and roots. Its yellow-green stems, which have some photosynthetic activity, are often seen draped over low trees and shrubs. It extracts its water and minerals from a host plant by means of haustoria, root-like organs that grow into the host tissue. Although now considered a pest, its place in our ecosystem was probably once controlled by frequent fire.

Twenty years after the founding of the Florida Native Plant Society, the need for conservation and education are still urgent. We have had many successes, and may rest in the shade of Redbay trees kept from the bulldozer, but we will never rest on our laurels.

Richard Moyroud
The Dahoon, Vol. 19, No. 4, April 2000