The bottle gourd, or calabash is originally indiginous to Africa, and is one of mankind's first widespread domesticated plants, due to it's food and medicinal properties.
The fruits are known to have fallen and floated in the sea for months at a time, explaining how the bottle gourd has thrived throughout the tropical climes of Asia.
Known in Thailand as the Namtao, it is popularly used in Thai food, especially in Thai green curry.
It is widely grown in domestic garden settings throughout Thailand, due to it's perfect fit with the Thai's love of owning useful food bearing plants within the garden. The skin can also be dried and used as a calabash container.