More commonly known as "bitter orange", the bitter orange is a tree native to Asia. Please note not to confuse the essential oil of sweet orange (Citrus sinensis) with that of bitter orange (Citrus aurantium). Bitter orange, or bigaradier, gives smaller and inedible fruits, leaves and branches provide the essential oil of small grain, while its flowers will be extracted from the essential oil of neroli. Bio essential oil indicated in cases of insomnia.