pinetum

from WordNet (r) 3.0 (2006)

pinetum
    n 1: an area planted with pine trees or related conifers

from The Collaborative International Dictionary of English v.0.48

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.
   [1913 Webster]