The Collaborative International Dictionary of English v.0.48:

Snakewood \Snake"wood`\, n. (Bot.)
   (a) An East Indian climbing plant (Strychnos colubrina)
       having a bitter taste, and supposed to be a remedy for
       the bite of the hooded serpent.
   (b) An East Indian climbing shrub (Ophioxylon serpentinum)
       which has the roots and stems twisted so as to resemble
       serpents.
   (c) Same as Trumpetwood.
   (d) A tropical American shrub (Plumieria rubra) which has
       very fragrant red blossoms.
   (e) Same as Letterwood.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Letterwood \Let"ter*wood`\ (-w[oo^]d`), n. (Bot.)
   The beautiful and highly elastic wood of a tree of the genus
   Brosimum (Brosimum Aubletii), found in Guiana; -- so
   called from black spots in it which bear some resemblance to
   hieroglyphics; also called snakewood, and leopardwood. It
   is much used for bows and for walking sticks.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Trumpetwood \Trump"et*wood`\, n. (Bot.)
   A tropical American tree (Cecropia peltata) of the
   Breadfruit family, having hollow stems, which are used for
   wind instruments; -- called also snakewood, and trumpet
   tree.
   [1913 Webster]

WordNet (r) 3.0 (2006):

snakewood
    n 1: East Indian climbing shrub with twisted limbs and roots
         resembling serpents [syn: snakewood, Rauwolfia
         serpentina]