Monday, September 17, 2007
Wood Nettles survival tip
Bottomlands and along streams in shady areas.
Appearance: Perennial herb up to two feet tall with stiff hairs on the stem.
Things to Look For: Stiff hairs on the plant's stem. Each tiny hair on the stems and leaves is hollow with a jagged point at the end. A bump against the stiff hair squeezes an irritating acidic chemical through the hair and onto a passing person's skin, much like a hypodermic needle.
The acid in the hairs, formic acid, is the same substance that many ants secrete to protect themselves from predators. In the Stinging Nettle, it's pressurized so that it bursts out the instant the sharp hairs make contact with skin. The acid quickly spreads into the nearby human skin cells, causing them to swell. A rash appears on the surface of the skin and small white spots develop.
Treatment if Exposed: Apply lotions with an anti-inflammatory and cooling effects (talc, calamine). Home remedies include to rub the irritated area with juice of dock (Rumex spp.) or Jewelweed (Impatiens capensis). Since the source of the irritation is an acid, it can also be neutralized by applying a base. Baking soda mixed with water works particularly well.
Human Reaction: Rash and dermatitis with an intense burning sensation due to allergic reaction.