are smooth, shiny seeds from two species of leguminous shrubs
, Caesalpinia bonduc
and C. major
, both known by the common name warri tree. C. bonduc
produces gray nickernuts, and C. major
The seeds are used to play mancala games such as oware in the Caribbean. The nickernut is marble-like and good for other uses, such as for jewelry.
Nickernuts are also said to contain arsenic.