Smooth-bark Mexican Pine, Pinus pseudostrobus

Smooth-bark Mexican pine (Pinus pseudostrobus) grows near Northern El Salvador, the highlands in Guatemala, and West Honduras and central Mexico. This tree has also been introduced to New Zealand. Fifteen mature Mexican pines can be found in the Palo Verde County Park located in Imperial County, CA.

This tree grows from heights of 65.6 feet to 131.2 feet and occasionally may reach 147.6 feet. It can be found growing from 4265 feet in elevation to 10,660 feet; although, this tree has done well at sea level in New Zealand. This pine grows best in volcanic soils as well as soils containing calcium carbonate, calcium, or lime. This pine can also withstand some freezing in the winter months and only 23.62-78.74 inches of rainfall annually.

The trunk of the tree measures 0.39 inches at DBH, growing straight with long branches that are spreading and ascending with the branches becoming slender higher in the tree. The crown makes up the majority of the tree height reaching 50-67%. The bark is smooth and red-brown to grey-brown in young trees and becoming thick, scaly, and darker with age. Needles grow in bundles of five at the ends of branches that are turned up and measure anywhere from 7.0 – 13.7 inches long. The needles are yellow-green, straight and will hang on for two to three years. Female cones grow in clusters at the end of new shoots, oval in shape and measures 0.78 – 1.37 inches long. The cones are yellow when immature and mature to brown. Seed cones grow in pairs or singularly and take two years to mature. The seeds are oval and measure .11-.177 inches long with wings measuring .78-0.98 x 0.27-0.39 inches long.

The Smooth-bark Mexican pine is used as firewood, pulpwood, as well as for general construction and for making decorative items. This pine is susceptible to the dwarf mistletoe fungus as well as several insects that cause damage to the cones and seeds.

Image Caption: Smooth-bark Mexican Pine (Pinus pseudostrobus) needles. Credit: Stan Shebs/Wikipedia (CC BY-SA 3.0)