Araucaria araucana

The Araucaria araucana, also known as the pewen, monkey-puzzle, pehuen, or Chile pine, is a tall evergreen tree that can grow up to 30–40 metres (about 98–131 feet) high. It belongs to the Araucariaceae family and is known for its thick trunk, which can be about 1–1.5 metres (3.3–4.9 feet) wide. This tree is native to central and southern Chile and western Argentina, making it a special part of these places.

The Araucaria araucana is very important to the people of Chile and the province of Neuquén, as it is chosen as their national tree. However, this tree faces serious problems that have made its numbers go down. In 2013, experts changed its status to Endangered because of things like cutting down too many trees, forest fires, and animals eating its young plants. These challenges make it important for people to help protect this beautiful tree so it can continue to grow and be a symbol of these regions.

Description

The leaves of the Araucaria araucana tree are thick, tough, and triangular, measuring about 3–4 cm (1+1⁄4–1+1⁄2 in) long. They stay on the tree for up to 24 years and cover most of it, except for older branches.

This tree usually has separate male and female cones on different trees. The male cones are oblong and grow to about 8–12 cm (3–4+1⁄2 in) long. The female cones are large and round, about 12–20 cm (4+1⁄2–8 in) in diameter, and they hold around 200 seeds. The thick bark, up to 15 cm thick, may help protect the tree from wildfires.

Taxonomy

The closest living relative of the Araucaria araucana is Araucaria angustifolia, a South American tree found in Brazil and northeastern Argentina. It looks similar but has narrower leaves and shorter spines on its seed cones. Other trees in the same genus, like Araucaria cunninghamii, Araucaria heterophylla, and Araucaria bidwillii, grow in the Pacific Islands and Australia.

Habitat

The Araucaria araucana tree grows naturally on the lower slopes of the Chilean and Argentine south-central Andes, between about 1,000 m and 1,700 m above sea level. It can also be found in the Chilean Coast Range as far south as Villa Las Araucarias, at an altitude of 640 m. Young trees start with a pyramid shape, but as they grow older, they develop a unique umbrella-like form. This tree likes soil that drains well and is slightly acidic, often found in volcanic soil, though it can grow in many types of soil if the drainage is good. Young trees usually grow in open spaces where they can get enough light to survive.

Seed dispersal

Araucaria araucana is a type of tree that produces seeds in large amounts at once, called masting. Small rodents, especially the long-haired grass mouse, are very important for spreading these seeds. This mouse buries the seeds in good spots where they can grow, which is different from other animals. Another helper in spreading the seeds is the austral parakeet. Big natural events, like volcanic eruptions, do not easily harm adult trees, and after such events, parakeets help by carrying seeds to new places far away.

Threats

Logging was a big problem for these trees, but it was stopped in 1990. Large fires in 2001–2002 burned many acres of forest and destroyed trees that were over 1300 years old. Other threats include animals eating the seeds, overgrazing, and people taking too many seeds, which stops new trees from growing.

Cattle ranching also makes it hard for new seedlings to grow. Studies show that both native and non-native animals can harm the tree’s ability to reproduce, though it’s not clear which is the bigger problem.

Cultivation and uses

The Araucaria araucana tree is popular in gardens for its unique, thick, symmetrical branches. It grows best in cool, rainy climates and can survive very cold temperatures. You can find these trees in parts of Europe, North America, and the southern hemisphere.

The seeds of the Araucaria araucana are edible and similar to pine nuts. People in Argentina and Chile have harvested these seeds for food for a long time. The tree can produce many seeds, but it takes about 30 to 40 years for it to start producing them. The wood of this tree was once highly valued for building and making products, but now it is protected and rarely used.

Etymology

This special tree was first seen by Europeans in Chile in the 1780s. It was named by a scientist named J.I. Molina in 1782. Later, other scientists gave it new names, but in 1873, the name Araucaria araucana was settled on.

The name "araucana" comes from the Araucanians, the native people of Chile. They used the tree's seeds for food. A group of them, the Pehuenches, got their name from eating these seeds, called pewen or pehuén in their language. They believe the tree was given to them to feed their children.

The English name "monkey puzzle" started in Britain around 1850. A man named Charles Austin said it would puzzle a monkey to climb the tree, and the name stuck.