How to Identify a Plant in 10 Steps

Whether you’ve encountered an interesting plant in the wild or simply come into possession of an unknown houseplant or garden plant, knowing how to identify a plant is a helpful skill to cultivate for both safety and plant care purposes. Baseline knowledge of botany and plant varieties is always a good starting place. Beyond that, you can follow a few steps to identify the general species of a mysterious plant.

1. 1. Note the climate and region. The biggest key to identifying a plant is to note the surrounding environment and its conditions. Use your surroundings to inform which potential varieties of vegetation you may find. For instance, evergreens are common in coniferous forests in cold regions. Succulents and cacti are more common in desert climates with low moisture and sandy soil. Algae, ferns, and tropical flowers are most common in humid, moist climates.
   
2. 2. Observe stems and branches. Look for any distinct characteristics on the stalks and branches of the plant, which can provide clues to its nature. Stems and branches that contain hardwood are usually woody plants, while soft, flexible branches are characteristic of herbaceous plants (which usually occur as perennials or annuals). Plants with trailing or climbing vines might be a type of ivy, fruit shrubs, or climbing plants in the broad bean family (Fabaceae).
3. 3. Note the leaf shape and size. The shape and size of the plant’s leaves can help determine its species. Broad, wide leaves might indicate a tropical plant, while pointy pine needles may indicate an evergreen species (unless you’re dealing with a broadleaf evergreen variety). Triangular leaves may indicate herbaceous plants, while thick, waxy leaves may indicate succulents.
4. 4. Check the leaf arrangement. Observe the formation and structure of the plant’s leaves, which can provide you with abundant clues to its species. (Leaves will also be present at any point in the plant’s growing season, not just during a flowering period.) Count the lobes on the plant’s leaves and note whether its edges are smooth or notched. Clusters of three blunt-toothed leaflets can mean poison ivy, while rounded lobes mean poison oak. Together, these details can help narrow down the type of species you see and tell you if the plant is safe to touch.
5. 5. Note fruits and flowers. A flowering plant’s berries and fruits can help you identify its species. Blue, black, and purple-skinned fruits are often edible, while green, white, and yellow berries are likely poisonous. (Always perform an edibility test before consuming any plant’s berries.) Figuring out the plant's toxicity is another essential step for identification. Check the flower color and number of petals to see if you’re dealing with weeds or wildflowers, some of which may be edible (like dandelions or chicory, which have many petals). However, most plants with umbrella-clumping flowers have high toxicity, which you should avoid.
6. 6. Look for barbs, hairs, or thorns. Inspect the plant for any defense-related characteristics like barbs, hairs, or thorns on its leaves or stems. Stinging nettle contains needle-like hairs on its stems. Some poisonous mushrooms secrete milky sap from their skin. Touching these plants can cause skin irritation, so it’s best to avoid physical contact with these plants if you see them outdoors.
7. 7. Note the smell. Some herbs (like parsley, rosemary, and basil) have aromatic scents, while others give off noxious odors. Plants with naturally sulfuric or fecal smells can also hint at what type of plant species you’re interacting with, such as crown imperials or female ginkgo trees.
8. 8. Check the roots. If you can safely handle the plant, check its roots to see how it grows (either from rooted stems, rhizomes, bulbs, or tubers). Underground rhizomes expand horizontally, developing new root systems and sprouting new shoots from nodes. Common rhizomes plants include lily of the valley, asparagus, and ginger. Bulbs have swollen underground stems similar to tubers, but their growth patterns are different. Daffodils, hyacinths, and tulips are all bulb plants. New bulbs grow from the base of the original bulb, while tubers develop buds on their surface, and new stems sprout from there. Many flowering plants such as dahlias, daylilies, and peonies have tuberous roots.
9. 9. Do your research. It is important to note that you will likely not be able to identify a plant based solely on a singular characteristic, and many plants have toxic doppelgängers out in the wild. Before relying on your eyes and experience, research plant anatomy and structures before touching or consuming unknown plants outdoors. Read research and reports authored by reputable botanists. Before bringing home cuttings to plant in your garden, learn about potentially invasive species, lest a foreign plant takes it over.
10. 10. Use a plant identifier app. Rather than relying on your own field guide, download a smartphone plant identification app, which uses artificial intelligence to find a specimen’s scientific name, common names, and general properties with a single photo of the plant. Most programs contain an in-app camera feature that allows you to take a picture of the plant and input particular characteristics. The app will check its appearance and characteristics against the species in its plant database to help find the plant ID.

Grow your own garden with Ron Finley, the self-described "Gangster Gardener." Get the MasterClass Annual Membership and learn how to cultivate fresh herbs and vegetables, keep your house plants alive, and use compost to make your community—and the world—a better place.