NPR identifies the jackfruit as the largest tree fruit in the world. Jackfruits can weigh up to 100 pounds, and Wikipedia notes that they can grow to 36 inches long and 20 inches in diameter. Four-foot jackfruits have been seen in India.
Jackfruits are high in potassium, vitamin B and vitamin C. The seeds of jackfruit are high in protein, and they can be roasted, boiled or ground into flour. The fruit is eaten raw, canned or processed into products that include chips, juices and ice cream.
Jackfruit trees are native to South and Southeast Asia, and they are also grown in Africa, the Caribbean and Brazil. According to The Guardian, jackfruit may be an answer to global food insecurity. It takes at least five years for a jackfruit tree to begin bearing fruit, but the tree requires very little care once it is established.