Coniferous trees are the most common type of gymnosperm, which are plants that produce seeds on the surface of cones. They are also known as softwood trees, a term that refers not to the firmness of the wood but to the fact that they bear cones and have needle- or scalelike leaves. They are often referred to as evergreens, even though not all conifers retain their leaves year-round. Although there are hundreds of different coniferous trees, most of them fall into one of 11 groups.
Pine trees (Pinus spp.) include a little over 100 species. They are the most common type of coniferous tree. They have long, narrow needles bound in bundles of two, three or five. Their branches usually grow in rings known as "whorls." Each whorl represents a year of growth. They are typically tall trees that like sunny locations and acidic soils.
Cedar trees can be divided into two groups: true cedar and false cedar. True cedar (Cedrus spp.) have evergreen needles that form in dense clusters out of stout, woody pegs. Their cones are barrel shaped and sit on top of the branches. True cedar is native to the Mediterranean and Himalayas.
False cedar is a term used to refer to several genus of conifers that have similar features. These features include small, scalelike leaves that overlap; small, upright cones that remain on the tree; and aromatic wood. Examples of false cedar include arborvitaes (Thuja spp.), white cedar (Chamaecyparis thyoides) and Eastern red cedar (Juniperus virginiana).
True firs (Abies spp.) are also called balsam firs because they have tiny pockets of resin, or balsam, in their bark. Their cones are erect and stand upright on the topmost branches. Leaves are typically 1-inch long and highly aromatic. The Douglas-fir (Psuedotsuga spp.) is not a true fir, but because of its similarity to true firs it is often grouped with it. It has also been called a pine, a spruce and a hemlock. Douglas-fir has very distinctive cones with pitchfork-shaped bracts.
Spruce trees (Picea spp.) have stiff sharp needles about 1 inch in length that grow from tiny wooden pegs. They appear very similar to fir trees, but have stiffer needles. Their cones hang down rather than stand up. Like pine trees, they have whorled branches.
Larches (Larix spp.) are different from other conifers because they are deciduous. Their 1-inch-long needles turn yellow in the fall before dropping. Their needles are also softer and not sharp like other conifers. Larches are also referred to as tamaracks.
Hemlock and Cypress
Hemlocks (Tsuga spp.) have short needles less than 1-inch long that emerge from small pegs. They are known for having tops and branches that distinctively droop. Cypress (Cupressus spp.) have very tiny leaves that are usually scalelike, but may be sharp and pointed. Their cones are round, woody and about 1/2 inches in diameter.
Redwoods and Sequoias
Redwoods (Sequoia spp.) have sharp needles that look like miniature swords. Redwood cones are about 1-inch long and have thick, wrinkled scales. Giant sequoia (Sqeuoiadendron spp.) are often confused with redwoods, but are very different. They have shorter needles and woody, egg-shaped cones that are extremely hard.
Junipers and Yews
Junipers (Juniperus spp.) and yews (Taxus spp.) might look like they produce berries, but they are actually fleshy cones. Juniper leaves may be either scalelike, needle-like or both. Juniper trees have a very distinctive, strong odour. Yew leaves are dark green on top and light green on bottom and distinctively pointed but not sharp.