Flowers are not the only ones to provide the precious aromatic substances constituting the raw materials of perfumers. Other parts of the plants (leaves, wood, barks, stems, twigs, resins, roots, fruits, seeds) complete their immense palette. Sometimes, various elements of the same plant can each provide a particular essence, like the bitter orange tree (Citrus aurantium), whose flowers give the orange blossom absolute, fruits the bitter orange essential oil, and woody parts the graze absolute. Such diversity explains the many different bottles on the shelves of the perfume laboratories.