Source : WordNet®

Rocky Mountain bristlecone pine
     n : small slow-growing upland pine of western United States
         (Rocky Mountains) having dense branches with fissured
         rust-brown bark and short needles in bunches of 5 and
         thorn-tipped cone scales; among the oldest living things
         some over 4500 years old [syn: {bristlecone pine}, {Pinus
         aristata}]