The Collaborative International Dictionary of English v.0.48:

Zamang \Za*mang"\, n. (Bot.)
   An immense leguminous tree (Pithecolobium Saman) of
   Venezuela. Its branches form a hemispherical mass, often one
   hundred and eighty feet across. The sweet pulpy pods are used
   commonly for feeding cattle. Also called rain tree. --J.
   Smith (Dict. Econ. Plants).
   [1913 Webster]