Pine, Bigcone Pinyon

views updated

Pine, bigcone pinyon

Pinus maximartinezii

division: Pinophyta

class: Pinopsida

order: Coniferales

family: Pinaceae

status: Endangered, IUCN

range: Mexico

Description and biology

The bigcone pinyon pine is a small, busy tree with a short trunk that is often contorted. It has widely spreading branches. They are spaced irregularly along the trunk and form an open, rounded crown. The tree normally grows to a height between 16.4 and 32.8 feet (5 and 10 meters), although some have grown as high as 49 feet (15 meters). Its trunk measures up to 19.7 inches (50 centimeters) in diameter.

The bark of the bigcone pinyon pine is dark brown in color and is broken into square plates measuring almost 4 inches (10 centimeters) in diameter. The needles usually grow in clusters of five. They are slender and flexible, and measure 3.2 to 3.9 inches (8 to 10 centimeters) long. The needles on most bigcone pinyon pines are covered with a removable waxy coating that gives them a whitish or bluish cast.

The most remarkable feature about this pine is its huge cones (hence its common name). Among the largest and heaviest pinecones, they measure from 5.9 to 9.9 inches (15 to 25 centimeters) long and 3.9 to 5.9 inches (10 to 15 centimeters) wide. The cones are covered in thick, woody scales that often curve down or backward. The cones contain wingless, edible seeds measuring almost 1 inch in length and 0.5 inch in width. Again, these seeds are among the largest pine seeds. The cones, which take about two years to ripen, hang from the branches like woody pineapples.

Habitat and current distribution

Bigcone pinyon pines are found in only one area in Mexico, near the village of Pueblo Viejo in southern Zacatecas. This village lies about 62 miles (100 kilometers) north-northeast of the city of Guadalajara. The trees occupy a range of 1.9 to 3.9 square miles (5 to 10 square kilometers) on the eastern flanks of a mountain range called Sierra de Monroe. In this area, the pines grow on dry, rocky ground. Botanists (people specializing in the study of plants) estimate that between 3,000 and 10,000 bigcone pinyon pines currently exist in this area.

History and conservation measures

This species of pine was first scientifically identified in 1964. Prior to this discovery, local inhabitants in the tree's range had been harvesting its seeds for many years. Although the seeds are a minor food source of people in the area, the gathering of seeds is not extensive. Many cones are left on the trees.

Fire is the main threat to the bigcone pinyon pine since the tree regenerates, or reproduces, slowly. Fires are frequent in this area, as farmers burn vegetation to clear land for crops. In 1986, an extensive fire devastated a large area, burning mature trees, seedlings, and saplings. No part of the bigcone pinyon pine's range is currently under protection.