And this is the cure for the Gympie stinger, and also the bull rout, a fish with poisonous spines that lies in river beds. Common bracken fern. The leaves in hot water are good. Or, just the crushed leaves moistened with spit if you're in the bush. The fiddlehead is much more potent, and more juicy, but care should be exercised. After removing the hairs (if possible) dab just a small amount on the site. The fiddlehead juice causes localised inflammation as part of it's healing process, take care to wash your hands after use, especially before you go to the toilet! 
RE: Nettle - 7 Health Secrets - Free Foraging