A large majority of conifer trees have straight trunks. They also exhibit strong apical dominance, a phenomenon where main branches are dominant over side branchlets. Apical dominance accounts for a narrow, cone-like shape. Conifer trees can grow in a myriad of sizes. The largest member of the family is the giant redwood. Redwoods in California's Sequoia National Park have been measured to grow taller than 375 feet. The smallest conifers, natural bonsai cypresses, typically do not exceed 10 inches.
Needle-like leaves typically characterize a conifer's foliage. Leaf sizes vary within the conifer family, ranging from a tenth of an inch to 15 inches long. Foliage formation helps conifers prevent the accumulation of snow on branches in the winter. This feature, along with a biochemical process known as hardening, makes conifers more resistant to freezing. A waxy leaf coating helps most conifers save water in the summer by reducing transpiration rates.
Conifers are wind-pollinated plants. The seeds of this family develop inside a protective cone known as a strobilus. Cones usually take between four months and three years to mature, and vary greatly in size. The cone-protected seeds of conifers are quite tolerant and can withstand harsh environmental extremes including heat, cold and drought. This durability allows conifer seeds to postpone their development until conditions are conducive to growth.
Conifer plants dominate the taiga. This terrestrial biome is located in the northern hemisphere and is characterized by its numerous coniferous forests. Taiga covers most of inland Canada and Alaska in North America and much of Sweden, Finland, Norway, Russia and Japan in Eurasia. Taiga, also known as the boreal forest, is the world's largest land biome and accounts for up to 30 percent of the world's forests. Dense growth of evergreen conifers can be found throughout this environment. Average annual temperatures in the taiga are second to only the terrestrial biome of the tundra.
Bristlecone pine conifers in California and Nevada have been dated to be nearly 5,000 years old. Tree ages are determined through a process known as dendrochronology. Core samples allow scientists to count tree-rings and determine age without killing the pines. A bristlecone pine tree named "Methuselah" in California's White Mountains was determined to be 4,789 years old in 1957.
