Plant Profile: White Mangrove, Laguncularia racemosa


By Kelsey Cooper, Rebecah Horowitz, and Katie Kara

Fig. 1. L. racemosa - pneumatocysts & paddle-
shaped leaves. Photo credit: T. Ann Williams.

This post is one of a series from professor Nisse Goldberg's Botany students at Jacksonville University.


Classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Myrtales
Family: Combretaceae
Genus: Laguncularia
Specific epithet: racemosa


Description
Laguncularia racemosa, or white mangrove, is a sprawling, woody shrub found in coastal habitats along West Africa, Northern South America, Mexico, the Caribbean Islands, and Florida. It can grow to be approximately 40 feet in height. In Florida, it is known to occur along the coast from Volusia County, around the southern tip of the state and northward on the Gulf side to Levy County. Laguncularia is a monotypic genus.

Figure 2. L. racemosa - flowers.
Photo credit: Glenn Fleming.
White mangroves' paddle-like leaves are oppositely arranged along the stem (figure 2). They have extra-floral nectaries -  glands at the leaf base that produce a sugary substance that wasps and ants like to eat. In turn, it is believed that these insects assist in protecting the plant from predation. Another interesting facet of white mangrove leaves is their ability to  "sweat" out salt.

Although it tends to occur close to saltwater, this is not because it requires salt, but because it tolerates salt - an attribute which gives it a competitive edge over many other plants. L. racemosa can survive periods of inundation in part because of structures called pneumatocysts (figure 1) which provide its roots with access to oxygen.

Figure 3. L. racemosa - fruits.
Photo credit: T. Ann Williams.
White mangrove produces relatively small white clusters of  flowers which blooms in the spring, (figure 2). Their petals are distinct, meaning they are not fused or connate. Small green fruits are produced from the flowers, with ridges running down the length of each fruit (Figure 3). The calyx that once made up the white flowers remains with the fruits. As with other mangrove species, the seeds remain on the mother plant during the period of seed maturation, detach, and then spend a required amount of time floating before they can establish.

The white mangrove is an important plant for numerous reasons. It serves as a windbreak along the coastline, its roots help slow erosion, and it provides birds, fish, and crustaceans with habitat for breeding, feeding, and nesting activities. Its wood is extremely durable and resistant to dry wood termites, but don't even consider cutting it down for this quality, as it is protected by the 1996 Mangrove Trimming and Preservation Act. Finally, its flowers are valuable to bees and apiculturists alike.

References

Comments

Post a Comment

Popular posts from this blog

Wednesday's Wildflower:Spanish Needle

Image
Spanish Needle, Bidens Alba Submitted by Donna Bollenbach, Suncoast Chapter Biden's alba , all photos by Donna Bollenbach Nothing attracts more butterflies and bees than a simple white flower called Bidens alba . Also called Romerillo, Beggar’s Tick, Spanish Needle or Monkey’s Lice, this Florida native wildflower is the third most reliable source of nectar for pollinators in our state. There would be many starving bees and butterflies if not for the Bidens family of flowers. More so, Bidens alba and its sister plant, Bidens pilosa , are both edible and have medicinal value. Yet, many gardeners have a love/hate relationship the plant, and some even consider it a pesky weed. Why?
Read more

Florida Native Azaleas

Image
Piedmont Azalea, Rhododendron canescens. Photo by Lilly Anderson-Messec By Lilly Anderson-Messec While growing up in North Florida, I began to recognize the arrival of spring by the boisterous show of white, pink, and fuchsia blooms of azalea shrubs. The house I grew up in had large, mature azalea hedges with a variety of different colors and forms. Every spring, my mom would bring in vases full of them and my dad loved to point out the showy shrubs as we drove through town. I suppose I assumed these plants were native, but most likely I never gave it a thought. I didn’t differentiate a native plant from a non-native one because I didn’t yet know the importance of native plants as the basis of our functioning ecosystems. I was so surprised when I learned the azaleas I was so familiar with (Rhododendron indicum) are actually transplants from Asia! They are favored by the horticultural industry for their fast, vigorous, and dense growth of evergreen leaves and large, showy blooms. Curio
Read more

Paradise Tree: Beautiful and Useful

Image
"The native Paradise tree is more useful than Google, and easy to grow." And how could any blogger resist leading off with this intriguing quote from the Key West Garden Club? I am a Master Gardener and a Master Naturalist, but I only know so much; so I always check out  statistics from experts before posting information about plants. I have a beautiful Paradise tree in my yard, it came from the raffle table at my chapter's program night about six years ago.   Paradise tree                Simarouba glauca For the first six years the little tree had a perfect, closed, cone shape; but just this summer I was astounded one morning to walk out and notice that my tree had changed. The canopy had begun to open up, there were open spaces between the layers of branches. It seemed to happen overnight. Proving again that a garden is constantly in motion, which is one of the fascinating things about observing them. Pinnate leaves of the paradise tree The leaves
Read more