rocky mountain bristlecone pine

Rocky Mountain bristlecone pine
    n 1: 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}, {Rocky
         Mountain bristlecone pine}, {Pinus aristata}]