Morphology: Plant Form And Structure

Learning to identify herbs, understand their structure, and recognize them in their native habitats can open a new dimension of appreciation for plants and the natural world. In fact, many herbalists believe that developing a bond with a healing plant by admiring its beauty, learning to recognize it in the wild, or growing it in a garden is part of the benefit that plant has to offer.

Plant Form And Structure

On a basic level, flowering plants are classified by the number and arrangement of their flower parts, so understanding flowers is extremely important in plant identification. Biologically speaking, flower parts are the plant’s reproductive organs, so they’re essential to plant survival. The colors, fragrances, and shapes that make flowers irresistible to humans also, in many cases, function to lure pollinators to visit and pollinate the plant, thereby producing the seed that becomes the next generation of the species.

Leaves, too, are vital to a plant’s survival. One of the main functions of leaves is photosynthesis, the process that causes plants to transform sunlight, water, and carbon dioxide into food (sugars) and oxygen. Leaves also produce a vast variety of chemicals in highly specialized cells and glands. These chemicals perform functions vital for plant survival (not all of which are completely understood) and give plants their characteristic tastes, colors, aromas, and medicinal properties.

Identifying Plants

One of the best ways to learn to identify plants is to become familiar with the characteristics of whole plant families, not just individual plants. This is easier to do than it might sound and can streamline the entire process of plant identification.

The reason is simple: Plant families display patterns that remain consistent from species to species. For example, flowers in the mustard family have four petals in a crosslike pattern and six stamens. Pea family flowers have five petals: two wing petals, one banner petal, and two petals fused into what botanists call a keel. And lily family flowers have three petals, three sepals, and six stamens.

Developing the ability to recognize family characteristics and identify plants takes a bit of practice and perseverance. Begin by looking closely at plants to become adept at recognizing subtle similarities and differences among them. How many petals does each flower have? Do the flowers grow singly or in clumps on the stem? Are the leaves shiny or fuzzy? Are they oval or pointed, round or heart-shaped? Are their edges smooth or serrated? How are the leaves arranged on the stems? Does the plant live in a shady habitat near water, or is it found growing only in dry, sunny locations?

Choose a particular plant and observe its life cycle as it grows throughout the seasons. Learn what it looks like as a seedling and when it is flowering. Watch as the flowers mature and produce fruits and seeds, and examine the seeds. Finally, see what happens as winter approaches and the plant dies back or enters dormancy. By becoming intimately acquainted with a plant in this manner, it will always be recognizable, like the familiar face of a friend in a crowd. The following 10 plant families, each of which contains numerous herbs, are a good place to start.

Basic Plant Structures

Plant morphology includes vegetative structures (stem, leaf, and root) and reproductive structures (such as flowers and fruits).

Basic Plant Structures

Plant Families

These 10 plant families offer an opportunity to explore a variety of plant characteristics.

Apiaceae (carrot and parsley family)

Asteraceae (aster and sunflower family)

Boraginaceae (borage family)

Brassicaceae (mustard family)

Fabaceae (pea family)

Lamiaceae (mint family)

Liliaceae (lily family)

Ranunculaceae (buttercup family)

Rosaceae (rose family)

Scrophulariaceae (snapdragon family)

While learning to identify herbs, a local field guide is an invaluable resource. Another good tool is a magnifying glass, which is helpful for examining small flower parts. The best kind of magnifying glass for plant identification is a jeweler’s loupe with a magnification of at least 10x.

Nontechnical field guides are often organized according to flower color, which can be helpful for beginners. Technical field guides, or floras, are more challenging because they utilize what is known as a dichotomous key. It functions as a sort of flowchart that requires you to choose between two options at each point in the identification process, necessitating a working knowledge of botanical terms.

Botanists use a rich variety of highly specialized words to describe plant characteristics. Don’t feel overwhelmed by the prospect of learning all of these terms. Become familiar with some of the most common ones, and look up unfamiliar words. Nearly all plant identification books provide a glossary of essential terms.

What Do I Need To Know?

For herb enthusiasts and gardeners, the most important categories of classifications to learn and understand are family, genus, species, and—when applicable—variety, cultivar, and hybrid. A good understanding of these will allow you to select, acquire, grow, and utilize the plants with the specific qualities you are seeking. Many people feel more comfortable using common names for plants simply because they are more familiar and easier to pronounce, and because plants can be purchased under those names from local nurseries and plant catalogs. If you feel intimidated by the thought of learning botanical names, consider that many common plant names—such as iris, crocus, chrysanthemum, and gladiolus, to name just a few—are actually scientific names that have been so widely used that they have become household words.