However, most tropical fruits are harvested from plants that are not amenable to this type of cultivation. So, we do not have easy access to the great diversity of fruits found in the tropics with the exception of bananas, pineapples and avocados. Citrus - trees with evergreen leaves, cultivated plants originated in SE Asia. Natural relationships are obscure, hundreds of taxa have been named but some researchers feel that all cultivated citrus came from 3 original species. Citrus easily forms stabilized hybrids so this adds to the confusion.
Fruit is an herperidium which is a berry with a tough skin formed by exocarp and mesocarp.
The skin has cavities filled with aromatic oils. Culture - cannot tolerate freezing temperatures, require soil moisture, sun and dry air. Bud grafting is most common method of propagation. Normals - Valencia, most popular, grown in Florida, juice orange. Navels - fairly recent, name refers to small ovary on top of regular ovary.