Sequoia sempervirens

The coast redwood, scientifically known as *Sequoia sempervirens*, is a remarkable evergreen tree.

It is the only living species in the genus *Sequoia*. These giants belong to the cypress family, known as Cupressaceae. They are famous for being the tallest living trees on Earth. Some individuals can reach heights exceeding 115 meters.

They are also among the longest-living organisms on the planet. A single tree can live for 1,200 to 2,200 years or even longer. Because of their size and age, they are vital to forest ecosystems.

The biology of the redwood is highly specialized for survival. They are monoecious, meaning a single tree produces both pollen and seed cones.

In the late winter, pollination occurs. The seed cones are ovoid, or egg-shaped, with 15 to 25 spirally arranged scales. Each of these scales holds between three and seven seeds. These seeds are small, with two wings that allow the wind to carry them away. Once the cone scales dry out at maturity, they open to release the seeds. This process allows the species to spread to new locations.

Physically, the coast redwood has several distinct features. The trunk is remarkably straight and can reach a diameter of up to 8 meters at breast height.

The bark is very thick, sometimes reaching 30 centimeters in depth. This bark is soft and fibrous, appearing bright red-brown when first exposed. The name "redwood" comes from this distinctive red heartwood. Unlike many other trees, their root system is shallow. Instead of growing deep, the roots spread out widely to provide stability. The leaves are also variable; they are long and flat on young trees but become scale-like on older trees in full sun.

Taxonomy, or the science of naming organisms, has evolved alongside our study of these trees. In 1824, the botanist David Don described them as *Taxodium sempervirens*. Later, in 1847, Stephan Endlicher established the genus *Sequoia*. The species name *sempervirens* translates to "evergreen."

This refers to the fact that they keep their leaves year-round. While the giant sequoia (*Sequoiadendron giganteum*) is a close relative, the coast redwood is its own unique genus. Recent molecular studies suggest the redwood may have even resulted from hybridization. This is a process called reticulate evolution, where two different species combine to create a third.

Redwoods occupy a very specific habitat along the Pacific coast of North America.

They live in a narrow strip stretching from Monterey County, California, to the southwestern corner of Oregon. They prefer mountainous areas where they can capture moisture from ocean fog. This fog drip is essential for their water needs. The tallest and oldest trees are often found in deep valleys and gullies. In these areas, year-round streams provide constant hydration. However, trees growing above the fog layer tend to be shorter and smaller due to wind and cold.

Genetically, the coast redwood is an extreme outlier. It is a hexaploid, meaning it has six sets of chromosomes.

This is unusual among conifers. According to Guinness, the coast redwood has the largest known genome of any plant examined up to the year 2020. Its genome totals 26.5 gigabases. This massive amount of genetic information is a significant subject for scientific study. It helps researchers understand how such large organisms function and grow over millennia.

The redwood plays a major role in global environmental systems. They are often called "carbon-sequestration champions." This is because they are excellent at capturing and storing carbon from the atmosphere.

Their ability to resprout from their root crowns after being felled or burned helps them maintain their presence in the landscape. Because of this, some groups are practicing "assisted migration."

They are planting redwoods further north in places like Washington state. The goal is to help the species adapt to a changing climate by reclaiming territory they once held during past geologic eras.