Solanum laciniatum Aiton Solanaceae. Kangaroo Apple. Evergreen shrub. Distribution: New Zealand and the east coast of Australia. It contains steroidal saponins that can be converted into steroids, including progesterone, oestrogens, cortisone, prednisolone etc. In 1943, Professor Russell Marker discovered a method of obtaining an unsaturated steroidal saponine, diosogenin, from Mexican yam (Dioscorea mexicana), which can easily and cheaply be converted into steroids, such as prednisone and progesterone, reducing the price of steroid production to a fraction (0.5%) of its former cost. For 20 years drug companies showed little interest, and it was only as a result of Professor Marker forming his own company, and the concerted efforts of several gynaecologists, physiologists and birth-control advocates, that the contraceptive pill was ‘born’ in 1960. Photographed in the Medicinal Garden of the Royal College of Physicians, London.