Medicinal Plants

Texas Junior Naturalists
An online resource for students of nature and the outdoors.

orange.gifMedicinal Plants

Did you know that plants are a major source of drug compounds. Approximately one-quarter of all prescription drugs contain an ingredient derived from a flowering plant. For example, digitalis, used in cardiac care, was derived from the ornamental flower Foxglove. A powerful anticancer agent for breast cancer has been found in Pacific Yew. And Periwinkle has yielded an anticancer compound that is useful against leukemia.

Scientists and pharmaceutical companies are constantly searching for new drug compounds in plants. The possibilities are endless, but there are limited resources to test new compounds. Indigenous peoples sometimes use plants for reasons that may not be scientific. For instance, spleenwort was used to treat spleen ailments because the leaves are shaped like that organ. However, many plants used did have medical properties. Native people had thousands of years to experiment with the plants around them, and often they can provide scientists with valuable information. Scientists who study native uses of plants are called "ethnobotanists."

Many potential medicinal plants have toxic compounds. However, compounds from the plant might still be usable in purified or minute doses. Doctors say that the difference between a medicine and a poison is the amount of the dose. Why so many toxic compounds? Often these are a plant's weapons against insects and other herbivores. Plants that can resist insects are also less likely to contract the plant diseases that insects frequently carry. This adaptation gives these plants an edge in surviving and reproducing. While you are in the field, notice whether plants with known toxins have been eaten less by insects than other plants.

Medicinal Plant Information

Compiled from Peterson Field Guide to Medicinal Plants by Steven Foster and James A. Duke


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