Whether you are pursuing a career in botany or you simply want to learn a little bit more about the plants that are growing in your own backyard, the following plant cuticle facts will come in handy the next time you come across a question regarding the proper way to care for the unique types of vegetation that are sprinkled across your landscape.
What are plant cuticles?
Plant cuticles are a protective coating that can be found in various places on different types of plants, most commonly on the outer surface of the leaves and shoots. Plant cuticles are waxy to the touch and produced by the epidermal cells, a single-layered group of cells on the roots, leaves, flowers and stems that create a boundary between the plant itself and the environment that surrounds it. Plant cuticles are the outermost portion of a plant and are comprised of an insoluble membrane that is covered with soluble waxes and polymers like cutin and cutan.
Several types of plants-particularly those with bark or woody layers-do not produce plant cuticles because they contain periderm, a cork-like tissue that serves as a protective layer for the plant instead. Trees, shrubs and a variety of forms of vines are all examples of plants that do not contain cuticles.
The purpose of plant cuticles
The primary function of a plant cuticle is to protect the plant from drying by holding moisture in and preventing it from evaporating into the environment. The presence of a cuticle in many plants is essential to their survival, as plants without cuticles that grow in environments characterized by extreme heat and intense direct sunlight would shrivel and dry up. In addition to preventing the loss of moisture inside a plant, plant cuticles also serve as a barrier against infection from bacteria, fungi and damaging organisms which could potentially enter the plant through its leaves if it didn't have a waxy layer present to protect it.
Types of plant cuticles
The type and thickness of plant cuticles vary from plant to plant and depend greatly on the amount and intensity of the sunlight the plant receives. For example, plants that grow in hot climates and receive direct sunlight often contain considerably thicker cuticles than plants that grow in cool, shady climates. Thicker plant cuticles prevent plants that take on intense heat and sunlight from drying out too quickly because the rate at which water escapes from the plant's tiny pores occurs much more slowly. Thinner cuticles allow plants in cooler environments to release water at a faster rate. Although most plants with thick cuticles are most often found in hotter environments and plants with thinner cuticles are more frequently located in cooler climates, exceptions to the rule do occur.