Limber Pine

On a beautiful day with fresh snow, the limber pines, pinus flexilis, wear white coats that nicely accent their green needles. This tree can also be known as a Rocky Mountain white pine, but I think that's in reference to the bark and wood rather than the snow!

According to Utah State's website, "Limber pine grows across a wider range of elevations that any other tree species in the central Rocky Mountains, inhabiting some of the driest sites capable of supporting trees. Most often found in more open and dry environments, and is typical on exposed, rocky mountainsides. It may be found in Utah from low elevations of about 4,000 feet right up to timberline near 11,000 feet."  The U.S. forest service lists the elevation range from 2850 feet in North Dakota to 12,500 ft. in Colorado.

Limber pine needles come in bundles of five, which make the branches seem rather bushy.  I think they resemble chimney sweep brushes of the kind used by Dick Van Dyke in Mary Poppins.

Limber pines are very common in the mountains east of Laramie and both the male and female cones are readily seen.
 
USU's website also explains that the name 'limber pine' comes from the fact that "the central trunk is usually distorted, many branched, and twisted."   This twisting ability of young trees to "withstand considerable bending, [is] a necessary trait for reforestation of snow avalanche paths, and much of the pine's natural habitat lies within avalanche areas." (na.fs.fed.us)  Or as the British Columbia forest service website put it: "Both the common name and flexilis refer to the flexible nature of the wood of this tree. Having flexible wood is an excellent adaptation for a tree that must deal with heavy snowpack and ice."

Limber pine is susceptible to numerous diseases and fungi, most of which have horrible sounding names.  These include white pine blister rust, crumbly brown cubical rot, brown felt snow mold and red-brown butt rot (also from the website na.fs.fed.us).  So with all of those potential pests, and the damaging dwarf mistletoe as well, it is nice to see healthy looking pines against a clear blue sky.

This species is a lot more uneven in its branches than many other conifers, so can sometimes be identified by its irregular shape.  Limber pine is intolerant of shade, so will take any amount of Wyoming wind and exposed rock in order to bask in the sunshine.