Galega officinalis L. Fabaceae. Goat's Rue. Distribution: Central and Southern Europe, Asia Minor. Culpeper (1650) writes that it ‘... resists poison, kills worms, resists the falling sickness [epilepsy], resisteth the pestilence.’ Galega officinalis contains guanidine which reduces blood sugar by decreasing insulin resistance and inhibiting hepatic gluconeogenesis.. Metformin and Phenformin are drugs for type II diabetes that rely on this group of chemicals, known as biguanidines. Its name gala, meaning milk plus ega meaning 'to bring on', refers to its alleged property of increasing milk yield, and has been used in France to increase milk yield in cows. officinalis refers to its use in the offices of the monks, and is a common specific name for medicinal plants before 1600 and adopted by Linnaeus (1753). The fresh plant tastes of pea pods. Photographed in the Medicinal Garden of the Royal College of Physicians, London.