Patchouli

Patchouli (Folium Patchouli), the leaves of Pogostemon patchouli Pelletier, a shrub of the Labiatae family, growing wild in the East Indies and Java, as well as from Plectranthus graveolens R. Brown of the same family (China, Tonkin), from Pogostemon Hayneanus Benth. and other plants, for example Microtaena cymosa Prain and M. robusta (northern India). An essential constituent of Patchouli is essential oil (up to 1¹/₂-2%, sometimes up to 4%); then Patchouli contains a green-colored resin, traces of tannins, and a bitter extractive substance. The essential oil (Oil of patchouli fol. aether.) is somewhat thick, possesses a strong odor, unpleasant to many, has the density of water, and rotates to the left. Upon cooling, crystals of solid alcohol, C₁₅H₂₅.OH, called patchouly camphor, separate from the oil. It is used in perfumery along with other essential oils. The leaves of Patchouli are used in medicine for aromatic pillows in cases of toothache.