Coconut
The coconut tree originally grew along tropical coasts, but humans valued their fruit so highly that they spread them much further inland.
#Human usage
People of the Fifth World use coconuts for all kinds of purposes. They eat the meat, sometimes drying strips of it to eat while on hunting or sailing trips. They also drink the water and milk, sometimes mixing the milk with other beverages such as coffee or cocoa.
Like many other palms, coconut palms can be tapped for palm wine, a popular beverage. Coconut water can also be fermented to make wine.
#Specialization
A community that specializes in relationship with coconuts may live near the coast, as coconut palms grow well along beaches. People who take long sea voyages will often take coconuts with them as portable sources of water and food. Such communities will have strong skills in boat- and raft-building; and many of their members will likely become quite cosmopolitan, traveling widely and speaking multiple languages. Thus, they'll also likely value and develop strong diplomatic skills.
Or they may practice horticulture, and therefore live in settled villages where they grow coconut palms themselves. Often these communities practice slash-and-burn agriculture, growing different guilds of plants at different stages and moving around the jungle in a regular cycle.
Communities with strong relationships to coconuts will invariably value climbing ability highly, as they will have to climb very high to collect the coconuts. They may also specialize in relations with monkeys, having community members who ally with monkeys to harvest coconuts from the tallest trees. Such people would learn the ways of the monkeys, how to speak to them, how to work with them, and even get wrapped up in the politics of the local monkey troop.