Kathy Willis is the director of science at the Royal Botanic Gardens in Kew, England. She is also a professor of biodiversity in the zoology department at the University of Oxford and an adjunct biology professor at the University of Bergen. She has authored or coauthored more than one hundred scientific publications, including the landmark book The Evolution of Plants. Kathy Willis lives in Oxford, England.

Katie Scott studied illustration at the University of Brighton before moving to London. Her clients include the New York Times and Nike. Her work draws influences from traditional medical and botanical illustration, both in aesthetic and subject matter. Katie Scott lives in England.