Scientific Name
Pinus strobiformis ‘Southwestern White Pine’
Southwestern white pine offers a fascinating example of how botanical classification, also known as taxonomy, continues to evolve and sometimes struggles with the uncertainties found in nature. Not long ago, the botanical name above appeared on lists of recognized pine species as distinct from limber pine (Pinus flexilis), despite the many similarities between the two. Some botanists considered this tree to be a limber-like variation of southwestern white pine, whose primary and undisputed population center lies in Mexico.
More recently, because these trees hybridize readily, the name Pinus reflexa has been used to describe intermediate forms between limber pine to the north and southwestern white pine farther south in Mexico. Rather than attempting to settle the debate, the proximity of these two trees at Regis conveniently allows visitors to compare them directly.
Most trees in this region identified as southwestern white pine originated from populations in Arizona, New Mexico or southwestern Colorado, generally at lower elevations than limber pines found higher in the Rocky Mountains. Southwestern white pines have typically grown to around 100 feet tall or slightly more, generally taller than “true” limber pines. The largest Colorado champion trees, located in the southwestern part of the state, measure 111 and 109 feet tall.
The five-needle foliage of the two species is quite similar, though the cones of southwestern white pine are generally longer. Both trees are cold hardy in this region, tolerate summer heat well and are highly adaptable to different soil conditions.