Look through any account of traditional medicine from communities living close to nature (eg Native American, African and Australian peoples, the Maori, ancient Britons and Welsh, middle European, and Siberian cultures, and island communities everywhere) and it is not surprising to see that wound-healing remedies dominate. Firstly this was one of the most urgent health priorities and secondly plants are very good at this!
Prominent in these lists are plants rich in tannins, found in barks, woody parts, broadleaf tree leaves and in many other plants. Tannins get their name because when animal skins are soaked in rich-red tannin solutions (especially popular are from oak bark and oak galls) their proteins coagulate (like boiling an egg) and they harden into tough leather. Washing and open wound with tannin-rich herbs boiled in water will similarly form a seal (eschar from the French for scar) that prevents infections, stops discharge and allows healing underneath. If you get wounded or burned out on a trail with no mobile phone reception, knowing this can save your life!
In emergencies wash the open wound with water that has cooked leaves or twigs from any broadleaved tree (oak is the best but most will do): it should be dark rich reddish brown in colour.