The Lecythidaceae comprise a family of about 20 genera and 250–300 species of woody plants native to tropical South America, Africa, Asia and Australia.

The Brazil nut is a South American tree in the family Lecythidaceae, and it is also the name of the tree's commercially harvested edible seeds. It is one of the largest and longest-lived trees in the Amazon rainforest. The fruit and its nutshell – containing the edible Brazil nut – are relatively large and weigh as much as 2 kg (4.4 lb) in total. As food, Brazil nuts are notable for diverse content of micronutrients, especially a high amount of selenium. The wood of the Brazil nut tree is prized for its quality in carpentry, flooring, and heavy construction.