Castor oil plant. 17th century artwork of a castor oil plant (Ricinus sp.), which is used in herbal medicine as a purgative (to discharge pus). Also seen is a Grass of Parnasus (at left, Parnassia sp., labelled with its original name Gramen pernassi), which is used as an astringent and tonic. At right is a bell flower (Campanula sp.). This artwork is taken from Basilius Besler's Hortus Eystettensis (1613), which illustrated over 1000 flowers and attempted an early pre-Linnaeus taxonomy, making it the largest and most comprehensive work of its time.