Caryocar nuciferum aka Butternut

Caryocar nuciferum is a large evergreen tree in the Caryocaraceae family. Its common names include souari nut and Guiana nut. Kew records its native range from Panama into northern South America. This includes Roraima in Brazil, plus St. Kitts and St. Vincent. It grows in wet tropical forests, including woods beside rivers. People gather its nuts from wild trees and sell them locally. Some growers also raise it in the West Indies.

The tree can reach 148 feet (45 metres) in height. Plants For A Future gives a spread of 98 feet (30 metres). These figures describe its large size, not a confirmed garden range. The trunk has buttresses at its base. The tree keeps its leaves year-round and grows at a moderate rate. Its size makes it a tree for sites with ample space. The sources give no further details about its leaves or bark.

Fruit takes about four months to ripen after flowering. Each fruit holds one to four seeds, most often one or two. The fruit may weigh up to 11 kilograms. A thick, hard shell surrounds each large, white kernel. People eat the kernels raw or cooked. They have a rich taste like almonds and contain over 60 percent fat. The seeds also yield edible oil for baking. People cook the yellow, oily fruit pulp before eating it. Plants For A Future lists no known hazards, but this does not establish safety for pets.

This tree needs a warm, humid climate and a sunny site. It grows best where daytime temperatures stay around 21–28°C. The sources list USDA zones 10–12. It prefers moist, fertile soil with good drainage. Deep, light loam and rich sandy soil suit it best. Poor soil and drought cause problems. Its preferred soil pH is 6–6.5, though it tolerates 5.5–7. Annual rainfall of 1,600–2,000 millimetres suits it best. Its exact soil and climate needs can make cultivation demanding.

Seeds may take six to twelve months to sprout. Young plants need a sheltered site with some shade from the sun. The tree has value as a food crop and food-forest tree. Its hard, durable wood suits canoes and curved boat parts. People make limited use of the timber because they value the seeds. Traditional medicine uses the plant to treat fever. The supplied sources give no specific pest or disease concerns.