Conifer plants include members of the division pinophyta and are commonly trees and shrubs with evergreen needle or scale leaves that produce seeds in cones. Wood is the structural tissue of conifers and most are very tall softwood plants with single trunks that populate the cool boreal forests in the northern hemisphere, although there are conifer plants in almost all climates. Conifer plants bear cones that reach maturity anywhere from four months to three years and that can grow to between 0.07 inches (2 millimeters) to 23 inches (58 cm) long. Conifer trees are often used in the production of paper and timber and as a result have significant economic value. Common conifer plants include pine, spruce, cedar, sequoia, redwood, fir, larch and juniper.
According to fossil records, conifer plants have been growing on earth for nearly 300 million years. Conifer plants grow in nearly all climates from the Arctic Circle to subtropical regions and produce resin that protects from fungus and insects. Some species can live extremely long lives such as the bristlecone pines that can survive for upwards of 5,000 years in the California and Nevada deserts. Other conifers are tall much like the sequoia of California’s Sierra Nevada that can grow to more than 312 feet (95 meters) in height. Others, such as New Zealand’s pygmy pine are shrubby and at maturity reach a height of less than 3.15 inches (8 centimeters). In addition, some conifers such as the cypress are deciduous and shed needle leaves annually while others do not.
Conifer plants reproduce by attaching seeds to the scales of cones that often fall to the ground. Once on the ground, they either decompose or open to release the seeds inside them that are then dispersed by the wind or small animals including birds. In some species such as the lodgepole pine, cones are typically released after a forest fire burns the tree, which may only occur every few decades. Pollination typically occurs when pollen released by a male cone is blown into a female cone and fertilizes the female gamete resulting in the development of seeds. Male and female cones are often found on the same conifer plant.
Many forests are populated with large conifer trees, but there are numerous species that are also suitable for the home gardener or landscaper to plant. Garden conifer plants are typically smaller shrub-like dwarf or miniature varieties with needles that range in color from green to yellow to blue and red. There are many available shapes as well, including round or globe shaped, prostrate plants that creep along the ground, and spreading conifers that are wider than they are tall. Additionally some conifer plants can be trained or pruned to form various shapes.