Large trees. Inflorescences terminal panicles. Flowers zygomorphic. Sepals 2. Fruits a large round woody pyxidium, 10-15 cm diam., with a small inwardly falling peg-like operculum. Seeds 10-25, triangular in cross section, the testa hard and woody, embryo undifferentiated.
The monotypic species Bertholletia excelsa is cultivated in various places such as in the grounds of the Forest Research Institute in Kepong, Malaysia, and in the Bogor Botanic Garden. This species is easily recognized by the hard woody fruit with hard woody seeds inside (Brazil nuts of commerce). Other notable features are the zygomorphic androecium with a hood of sterile appendages that covers the ring of fertile stamens beneath and the calyx which has only two lobes.