Clausena lansium, known as wampee or wampi, from the Chinese word for yellow skinned fruit. It is a species of strongly scented evergreen trees 3–8 m tall, in the family Rutaceae, native to southeast Asia.
Its leaves are smooth and dark green. White flowers appear in late March. The fruit is oval, about 3 cm long and 2 cm in diameter, and contains two to five seeds that occupy ~40-50% of the fruit volume. The tree reaches a maximum height of 20 meters. It grows well in tropical or subtropical conditions, and is susceptible to cold. Wampee trees grow well in a wide range of soils.
The wampee is cultivated for its fruit, which is a grape sized, fragrant citrus. Its skin and seeds are often eaten along side the pulp, much like kumquat. Apparently, wampees grow quickly and produce from their first year.
Let's hope citrus greening disease does not affect wampee in South Florida.
Where to buy: https://www.ebay.com/itm/303115536225