The Limber Pine, Pinus flexilis, is a pine native to the Northwest USA. It is a 5-needle pine easily misidentified in a bonsai collection as Pinus parviflora, the Japanese 5 needle pine.
The Limber pine grows at high elevations on the eastern slope of the Rocky Mountains. It is adapted to intense solar radiation, high winds and dryness. There are stands of these trees containing specimens many thousands of years old.
Used as bonsai they grow slowly but make beautiful trees. As with all pines grow them in an open granular soil mix and keep the roots from staying wet. Otherwise there seems to be no problems with this pine.
The needles are blue green and not stiff or spiky to the touch. The common name of Limber pine tells you that the branches are very flexible yet they accept wiring very well.
The tree in the picture is one that was purchased from a nursery in 1985 and estimated to be about 28-30 years old. The original top was sawed off and a dead wood apex was created to to shorten the 7 foot tree and to create the illusion of age.
At higher elevations a one inch trunk can signify one hundred years of age! As with all bonsai use caution in evaluating age of a tree by its appearance. A very similar species that grows mainly on the western slope of the Rockies is the Whitebark pine, Pinus albicaulis.