Juglans neotropica aka Andean Walnut

Juglans neotropica is the Andean walnut, also called tropical walnut. It belongs to the walnut family, Juglandaceae. Its native range spans western South America and parts of Venezuela. It grows in Colombia, Ecuador, and Peru. This deciduous tree lives in mountain forests, from dry to very wet sites. People also grow it in parts of the Andes. Wild trees often grow beside streams and along field edges.

This slow-growing tree needs space for its broad crown. Garden descriptions give a height of about 82 feet [25 metres]. Its spread can reach 59 feet [18 metres]. Other accounts report heights of 98–131 feet [30–40 metres]. The crown may be oval, spreading, or unevenly rounded. A straight, tapered trunk supports the main branches. Its thick, cracked bark has a reddish-brown tone. The leaves are compound, with several leaflets forming each leaf.

The tree is self-fertile and bears fruit that turns yellow-green when ripe. Each seed sits within a thick, hard shell. People eat the oil-rich seeds raw or cooked. They gather nuts from wild trees and sell them locally. The seeds have a rich taste and serve as a local food. The supplied sources report no known hazards. This does not establish safety for every use or for pets. People also boil the leaves for use as a tonic.

Grow it in sun, with shelter from strong winds. It needs moist soil that drains well. Deep, fertile loam suits it best. Soil pH guidance differs, so avoid assuming broad tolerance. Some accounts favour near-neutral or mildly acid ground; others favour slight alkalinity. Its mountain habitat lies at 5,249–9,843 feet [1,600–3,000 metres]. Reported preferred mean temperatures range from 14–22°C. PFAF lists USDA zones 10–12. Seeds need protection from birds and rodents during propagation. Young trees need cold protection during their first winters.

The tree supplies food, timber, dyes, and tannins. Its dark heartwood contrasts with the lighter sapwood. Woodworkers use it for veneers, cabinets, and indoor joinery. Bark, leaves, and fruits yield dyes of several colours. Growers also use it as rootstock for common walnut. Its broad crown and wildlife value suit spacious food-forest plantings. Habitat loss and timber cutting threaten wild trees. Useful Tropical Plants cites an Endangered assessment from 1998.