The Collaborative International Dictionary of English v.0.48:

Manchineel \Man`chi*neel"\, n. [Sp. manzanillo, fr. manzana an
   apple, fr. L. malum Matianum a kind of apple. So called from
   its apple-like fruit.] (Bot.)
   A euphorbiaceous tree (Hippomane Mancinella) of tropical
   America, having a poisonous and blistering milky juice, and
   poisonous acrid fruit somewhat resembling an apple.
   [1913 Webster]

   Bastard manchineel, a tree (Cameraria latifolia) of the
      East Indies, having similar poisonous properties.
      --Lindley.
      [1913 Webster]