Prof Kathy Willis, Director of Science at the Royal Botanic Garden, Kew, with the omnibus edition of her history of our changing relationship with plants during the early 20th century. Kathy Willis examines how the complete picture of photosynthesis led to new opportunities to manipulate plant growth; the ability of plants to exhibit multiple forms that shed light on why flowering plants evolved so quickly; the legacy of tree diseases during the 20th century; the hunt for wild ancestors of our domestic crops in order to maintain resilience within our future food supplies; and botanical medicines and the hunt for new medicinal cocktails at home and abroad. Producer Adrian Washbourne.