Petitgrain oil is produced from the leaves and twigs of the bitter orange tree (Citrus aurantium amara), a member of the Rutaceae plant family. 
These evergreen trees can grow up to 6 metres in the wild, but will only grow to half this height in cultivation. 

It is mainly distilled by small farmers and delivered in small quantities to local traders (collectors), who then test, batch and resell the product to export houses. Harvesting and distillation are done during October and March. 

The tree produces a distinctive 'double leaf', which has a small bulge at the base of the main leaf. Its fruit is used to flavour liqueurs, such as Grand Mariner and Triple sec, and its flowers provide neroli and orange blossom oils, It is also used widely in perfumery for its strong, bitter-sweet, citrusy odour with floral and woody notes.