Herbal trial and error becomes even more remarkable when we consider that cultures separated by thousands of miles arrived at similar uses for many healing herbs, apparently independently.
Herbal healing includes four major traditions: Chinese, Ayurvedic (in India), European (including Egyptian), and American Indian. Until the 15th century, Old World cultures were isolated from the Americas. Nonetheless, Old and New World herbalists used many herbs similarly.
Angelica and licorice: Asians, Europeans, and Native Americans all used these herbs to treat respiratory ailments.
Hop and the mints: All the ancient herbal traditions used these herbs as stomach soothers.
Blackberry and raspberry: These two popular herbs have been used around the world to treat diarrhea.
Uva ursi: Asians, Europeans, and Native Americans all discovered this herb's diuretic properties.
White willow: All the herbal traditions used this herb to treat pain and inflammations.
During the 19th century, chemists used this "herbal convergence" to point them to the plants that provided extracts for the first pharmaceuticals. According to a report published in the journal “Science”, of the 121 prescription drugs derived from higher plants, about 74 percent came to drug companies' attention because of their use in traditional herbal healing. (‘The Healing Herbs’, the ultimate guide to the creative power of Nature’s medicine’, by Michael Castleman)