The Collaborative International Dictionary of English v.0.48:

garambulla \garambulla\ n.
   1. An arborescent cactus of Western Mexico (Myrtillocactus
      geometrizans) bearing a small oblong edible berrylike
      fruit.

   Syn: garambulla cactus, Myrtillocactus geometrizans.
        [WordNet 1.5]

   2. The small berrylike fruit of the Myrtillocactus
      geometrizans.
      [WordNet 1.5]

WordNet (r) 3.0 (2006):

Myrtillocactus geometrizans
    n 1: arborescent cactus of western Mexico bearing a small oblong
         edible berrylike fruit [syn: garambulla, garambulla
         cactus, Myrtillocactus geometrizans]