The Collaborative International Dictionary of English v.0.48:

Monkey-pot \Mon"key-pot`\, n. (Zool.)
   The fruit of two South American trees (Lecythis Ollaria,
   and Lecythis Zabucajo), which have for their fruit large,
   pot-shaped, woody capsules containing delicious nuts, and
   opening almost explosively by a circular lid at the top.
   Vases and pots are made of this capsule.
   [1913 Webster]