Taking the Itch Out of the Rash
A longstanding belief that has it roots in Native American folklore is that the crushed leaves of jewelweed (Impatiens capensis) relieve the skin's allergic reaction to the toxin of poison ivy (Toxicodendron radicans). This case was developed for an introductory majors or non-majors biology or plant class. It first examines students' conceptions about the rash of poison ivy, what in the plant causes the rash, and how the body responds to the toxin. Then students in small groups plan an experiment using the scientific method to test the ability of jewelweed to reduce the reaction. Following a comparison of experimental designs from different groups, data from a scientific paper is presented for interpretation and analysis. An important outcome of this case is that students recognize the need for evaluating myths and misconceptions using scientific evidence.
- Analyze information for the purposes of developing and evaluating hypotheses, making predictions, designing experiments, interpreting data, and drawing conclusions.
- Increase knowledge about the poison ivy plant and the body’s response to exposure to the plant.
KeywordsPoison ivy; Toxicodendron radicans; urushiol; jewelweed; Impatiens capensis; allergic reaction; contact dermatitis; ethnobotany; natural products; experimental design
Topical AreasScientific method
Educational LevelHigh school, Undergraduate lower division
Type / MethodsInterrupted, Journal Article
Subject HeadingsBiology (General) | Botany / Plant Science | Science (General) | Toxicology |
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