Larix is a genus of coniferous trees, or trees that have seed cones, which includes all of the trees known as larches. Larches are unusual coniferous trees because they are deciduous instead of evergreen, meaning that they lose their needle-like leaves every year when the weather turns colder. The trees are native to the temperate forests of Europe and northern Asia, but they are also found growing in North America. Common species such as Larix europea and Larix decidua can be found at tree nurseries and planted for landscaping purposes. The wood of the larch also has uses in industry and its bark and resin are used in herbal medicine.
Trees of the genus Larix are fast-growing, and can typically reach great heights of between 50 to 100 feet (15 to 30 meters) during their lives. Like most coniferous trees, they have long, thin, needle-like leaves that grow in clusters. Their seed cones can be red, purple, or green when young, turning deep brown at maturation. The bark of the trees also changes color with age, starting out as a silvery or gray-brown color when the tree is young and eventually developing into a reddish brown color.
In the lumber industry, Larix species are valued because they are solid and long-lasting, and can be cut into boards that have few knots. Lumber from these trees also has waterproof properties. Since the wood is waterproof, it is often used to build small boats or on housing exteriors. Historically, waterproof boards cut from larch trees were used to build the frameworks for military vessels. Another historical industrial use for larches is found in traditional tanning processes that use tree bark, although the bark of the larch is not as effective as the bark of oak in tanning.
The bark and resin of larches are also used in herbal medicine. These plant parts contain an organic compound made up of sugars called arabinogalactan. This compound is considered a good source of dietary fiber and provides support to the immune system. Larch arabinogalactan is usually found in the form of powdered bark or resin, which is usually ingested by dissolving the powder in a glass of water and drinking it. This powder can be taken to treat a variety of respiratory ailments, such as colds and flu, and may also be helpful in cancer treatment because it appears to increase the efficacy of medications taken during chemotherapy.