Source : Webster's Revised Unabridged Dictionary (1913)

Tamarisk \Tam"a*risk\, n. [L. tamariscus, also tamarix,
   tamarice, Skr. tam[=a]la, tam[=a]laka, a tree with a very
   dark bark; cf. tamas darkness: cf. F. tamarisc, tamarix,
   tamaris.] (Bot.)
   Any shrub or tree of the genus {Tamarix}, the species of
   which are European and Asiatic. They have minute scalelike
   leaves, and small flowers in spikes. An Arabian species ({T.
   mannifera}) is the source of one kind of manna.

   {Tamarisk salt tree}, an East Indian tree ({Tamarix
      orientalis}) which produces an incrustation of salt.

Source : WordNet®

tamarisk
     n : any shrub or small tree of the genus Tamarix having small
         scalelike or needle-shaped leaves and feathery racemes of
         small white or pinkish flowers; of mostly coastal areas
         with saline soil