Columbine flowers. 17th century artwork of flowers from three columbine (Aquilegia sp.) plants. These plants are used in herbal medicine as diuretics (to encourage urination). Artwork from Basilius Besler's Hortus Eystettensis (1613). This book illustrated over 1000 flowers, attempted an early pre-Linnaeus taxonomy and was the largest and most comprehensive work of its time.