Sequoia sempervirens, the coast redwood, is considered as the tallest tree in the world. Also known as the California redwood or the giant redwood, these trees are know to grow up to a height of 115.52 meters (379 feet), and their diameter at breast height reaches up to 7.9 m (26 ft). They are also among the longest-lived trees, capable of reaching 1,200 to 1,800 years old, or even older.
The coast redwood has a cone-like crown, and its branches either stretch out horizontally or droop slightly down. It has a very thick bark, which can reach a thickness of up to 12 inches (30 centimeters), and is rather soft and stringy, with a red-brown coloration when it is freshly uncovered (thus earning the name “redwood”). The redwood has a root system made up of shallow, widespread roots growing sideways. Its leaves can vary in shape and size. They range in length from 0.59 to 0.98 inches (15 to 25 millimeters), and can be flat on younger trees, while those on older trees tend to have a scale-like appearance and be as long as 0.20 to 0.39 inches (5 to 10 mm).
Redwoods are monoecious, which indicates that their seed cones and pollen are found on the same plant. The seed cones have an oval shape, measure 0.59 to 1.3 inches (15 to 32 mm) in length, and have 15 to 25 scales arranged in a spiral. Pollination takes place late in the winter time, and it takes roughly 8 to 9 months for the maturation process to complete. Each one of the cone scales holds 3 to 7 seeds, with each of the seeds measuring 0.12 to 0.16 inches (3 to 4 mm) in length and 0.020 inches (0.5 mm) in breadth, and having a pair of wings with a width of 0.039 inches (1 mm). Upon maturing, the cone scales have dried up and open to release the seeds. The pollen cones are oval-shaped and measure in length from 0.16 to 0.24 inches (4 to 6 mm).
The current record holder for tallest tree is the coast redwood nicknamed Hyperion, which measures 379.3 ft (115.61 m). Hyperion was discovered by Michael Taylor and Chris Atkins during the summer of 2006 in Redwood National Park, California in the United States. Previously, the title of tallest tree once belonged to the so-called Stratosphere Giant, located in Humboldt Redwoods State Park, also in California. When it was last measured back in 2004, the Stratosphere Giant stood at 112.83 m. Another previous contender was the Dyerville Giant, also from Humboldt Redwood State Park, which measured a height of 113.4 m before it fell in March of 1991. The Dyerville Giant was also said to be approximately 1,600 years of age.