ABSTRACT
Ma kwaen, also called ma kaen in Nan Province, is the northern Thai name for a small forest tree found at altitudes between 350 and 1,000 m above sea level (asl) in northern Thailand and Laos. When mature, it is 5 to 10 meters tall and has a diameter of about 20 cm. It is found mainly in upland forest reserves and highland areas where the farmers have no legal title to land. When it is three to five years old, ma kwaen flowers in racemes. The seed pods have been harvested for generations by the northern Thai people in the cool, dry season in November and December. The pods are harvested just before the seeds mature and are then dried and sold in local markets. The black seeds are not eaten, but the seed coats contain an essential oil used for flavoring food. They are pounded by hand mortar and pestle and mixed with meat dishes and soups. They give a sweet lemon flavor to the food.
