Some cultures believed that plants have souls. In 4th century BC, Aristotle believed that plants had a psyche.
In medieval Europe, the Doctrine of Signatures stated there was a connection between how a plant looked (God's signature) and how it could be used medicinally, such as the Lungwort (which looks like a lung) which was/is used to treat respiratory illnesses.
For a sore throat
For healing wounds
To soothe your mouth/gums
Interesting texts: Chevallier, A. The Encyclopedia of Medicinal Plants, DK, London. 1996.
See also Herbs.