The genus name refers to the resemblance of its seeds to certain ticks, also called ricinus in Latin. Known by the name of croton by Greek authors, as Theophrastus and Dioscorides, the seeds appear occasionally in ancient Egyptian tombs. Supposedly originating from the Horn of Africa, the castor is scattered almost all warm regions of the globe, having been naturalized for being a plant cultivated since antiquity, in part, because of the pharmacological and industrial qualities of its oil, although, is also known to be highly toxic. Its use in gardening is also extended due to contrast that occurs between green leaves and red flowering. Easy to find, therefore, in many gardens in the city or on the banks of the Guadalquivir, its presence in the Alcázar is testimonial, reduced to a single specimen in the garden Rustico. Space, around which we can evaluate his reputation as an effective repellent for flies.