What is a pine tree?
Pines are conifers of the genus Pinus, which is estimated to have between 105 and 125 species. They grow throughout the Northern Hemisphere, and have also been introduced to temperate and subtropical regions for timber production. The tallest pine is a ponderosa (Pinus ponderosa), which is 268 feet (82 metres) tall. They are also extremely long lived, with the average lifespan of a pine reaching up to 1,000 years. One of the world’s oldest living organisms is a Great Basin bristlecone pine (Pinus longaeva), called Methuselah, and is thought to be around 4,600 years old.
Many species are adapted to live in extreme environments, especially high elevation and latitude. Others require regular forest fires in order for seeds to germinate, as the cones are sealed with resin which must be melted before the seeds can be released. While pines are usually associated with cold climates, some thrive in hot, arid habitats.
A distinctive characteristic of pines is the cone, which is used for reproduction. Most species are monoecious, meaning that each tree has both male and female reproductive organs. The male cones are smaller than the female cones, and they produce pollen for a short period before dropping off. The female cones receive the pollen and then take up to three years to mature, and can reach up to two feet (60cm) in length in some species. The cones are covered in scales, and each scale has two seeds. When mature, the cones open and the seeds are spread by the wind, although a few species rely on birds to break the cones open first.
Photo: Norfolk Island pines (Araucaria heterophylla) by Kahuroa on Wikipedia.