Dr Henry Oakeley was a psychiatrist whose main botanical interest for 50 years was in orchids, but for the last ten has been in the use of plants as medicines, from earliest times to the present day.

Jane Knowles has been in charge of the Garden at the Royal College of Physicians since 2005, after eleven years at the Chelsea Physic Garden as head of propagation and medicinal plants.

Prof Michael de Swiet is professor emeritus of obstetric medicine at Imperial College London and is particularly interested in medicinal plants and women's health. He also volunteers at the Royal Botanic Gardens, Kew.

Prof Tony Dayan was a neuropathologist before moving into toxicology, first in drug industry research and then in academia. His abiding scientific interest is in mechanisms of health and disease.