
Several species of lavender (genus lavandula) grow naturally in Provence. Two of them are mainly cultivated and processed by lavender growers: fine lavender and lavandin.
One hectare of fine lavender yields 15 to 20 kg of essential oil. For lavandin, yields vary between 60 and 150 kg of essential oil per hectare, i.e. from 3 to 10 times more!
History, species, essential oil… Check out the Wikipedia page on lavender!