As the monasteries grew in number, so did the cultivation of herbs in their gardens – and they became the centres of medicine as well as education. From this time date the oldest hospitals such as Barts in London, as well as the Leper houses. Several of the herbs mentioned in the treatment of leprosy -  Burdock, Goosegrass, Red Dock and Garlic are still around in various drugs. In the gardens of many of the large houses and rectories near abbeys and monasteries survive some ancient drug plants – including some that were used for their narcotic properties such as Deadly  Nightshade (Atropa Belladonna) , Henbane (Hyoscyamus Niger) and Woody Nightshade (Solanum Dulcamara).  In the middle ages a standard painkiller was the “soporific sponge” consisting of an infusion of mandrake (another of the family Solanaceae) Hemlock, Poppy, Lettuce, Ivy and Mulberry – this was soaked in a sponge and held to the patient’s nose.

Philippus Bombastus (who called himself Paracelsus) had a theory that every plant was “signed” or associated by colour, or habitat with the disease it would help to cure. Hence, the spotted leaves of Pulmonaria (Lungwort) were supposed to resemble lungs, so it should be good for chest ailments, and Eyebright, whose flowerslook like bright eyes, would be good for eye troubles. This, the “Doctrine of Signatures” was a load of rubbish – but still has its followers today.