Understanding the Confusion of 'Touch Me Not'
The name "touch me not" is an ambiguous label applied to several plants that share a common trait: a rapid, sensitive movement upon contact. However, this is where the similarities end, and the difference between a harmless foraging experience and a potentially dangerous one begins. The two most common plants referred to as "touch me not" are Mimosa pudica, also known as the sensitive plant or shame plant, and Impatiens capensis, more commonly called Jewelweed. While one is poisonous, the other offers some edible parts, but only if properly prepared.
The Toxic Sensitive Plant: Mimosa pudica
Contrary to some claims, the sensitive plant (Mimosa pudica) is not safe for human consumption in its raw form, especially in large quantities. The plant contains a toxic amino acid called mimosine. For livestock, consuming enough mimosine can cause hair loss and other health issues. For humans, large doses of mimosine can be acutely toxic and even fatal. While some traditional medicine systems have used parts of the plant, often as extracts or poultices, these uses are not a basis for casual, culinary consumption. Studies on oral toxicity in rats have shown adverse effects on organs like the liver and kidneys with repeated dosing, warning against its traditional use. Furthermore, the plant contains tannins, which can be toxic if ingested in high doses. Due to its antifertility properties, pregnant women are advised to avoid it entirely.
- Leaves: Used topically in some folk medicine for wounds but contain potentially harmful compounds if ingested.
- Roots: Considered toxic, particularly in large doses, and have been noted to cause sickness if eaten.
- Seeds: While some sources note oil can be pressed from the seeds, ingesting the seeds or their oil can negatively affect nutrient absorption.
The Edible Jewelweed: Impatiens capensis
Another plant commonly called "touch me not" is Jewelweed (Impatiens capensis), and it offers some truly edible components. Its name comes from its seed pods, which burst open and disperse seeds when touched, similar to the sensitive plant's movement.
- Seeds: These are the most prized edible part. They taste surprisingly like walnuts and can be foraged as a tasty trailside nibble. The only challenge is catching enough of them as they pop out of the pods.
- Shoots: The young shoots can be eaten, but must be boiled thoroughly in at least two changes of water. Raw consumption is not advised and can lead to gastrointestinal issues.
- Medicinal use: Jewelweed is famously used topically to relieve the itching and irritation from poison ivy and insect bites.
The Third "Touch Me Not": Impatiens noli-tangere
A final point of confusion can arise with Impatiens noli-tangere, or Western Touch-me-not. This plant contains calcium oxalate and can cause burning, irritation, and swelling of the mouth if ingested in large amounts, especially raw. It is best to avoid this plant culinarily, particularly for individuals with certain health conditions like kidney stones or gout.
Comparison: Mimosa pudica vs. Impatiens capensis
| Feature | Mimosa pudica (Sensitive Plant) | Impatiens capensis (Jewelweed) |
|---|---|---|
| Edibility | Not edible for humans, contains toxic compounds. | Edible, specifically seeds (raw) and shoots (cooked). |
| Key Feature | Leaves fold inward rapidly when touched. | Seed pods burst open explosively when touched. |
| Toxic Compound | Mimosine, a toxic amino acid. | Low toxicity, though raw shoots are not recommended. |
| Edible Parts | None safe for casual culinary use. | Seeds and cooked young shoots. |
| Other Uses | Traditional, high-risk medicinal uses for leaves/roots. | Topical remedy for poison ivy and other skin irritations. |
| Cautions | Avoid ingesting any part; especially dangerous for pregnant women. | Ensure proper identification; shoots must be cooked properly. |
Proper Identification is Non-Negotiable
Given the stark difference in edibility and safety, anyone considering foraging for plants with the "touch me not" name must be absolutely certain of its identity. Never rely on the common name alone. Mimosa pudica has delicate, fern-like leaflets and pink or purple, fluffy ball-shaped flowers. Jewelweed (Impatiens capensis), conversely, has distinctive orange-spotted, trumpet-shaped flowers. Observing the specific growth patterns, leaves, and flowers is paramount for safety.
Conclusion
To the question, "Can you eat touch me nots?" the answer is a decisive "it depends on the species." While the common name can apply to both edible and toxic plants, the most important rule is to differentiate between them. The sensitive plant (Mimosa pudica) is toxic and should never be eaten. In contrast, the seeds of Jewelweed (Impatiens capensis) are a delicious trailside snack, and its shoots are edible when cooked correctly. This example underscores a critical principle of foraging: never eat anything unless you are 100% confident of its identity. Always prioritize safety over assumption. Consult reputable sources and field guides to be certain, and when in doubt, do not eat it.
If you are interested in learning more about edible plants, consider joining a local foraging group or taking a class with a trained expert for hands-on guidance. The U.S. Forest Service provides resources and information on safe foraging practices and ethics [https://www.fs.usda.gov/wildflowers/ethnobotany/foraging.shtml].
Disclaimer: Always exercise extreme caution when foraging. Do not consume any part of a plant you cannot positively identify. Consult with a medical professional before using any plant for medicinal purposes. This article is for informational purposes only and does not constitute medical advice.
