Source : Webster's Revised Unabridged Dictionary (1913)

Pinetum \Pi*ne"tum\, n. [L., a pine grove.]
   A plantation of pine trees; esp., a collection of living pine
   trees made for ornamental or scientific purposes.

Source : WordNet®

pinetum
     n : an area planted with pine trees or related conifers
     [also: {pineta} (pl)]