Spruce

A spruce is a tall tree.

Its leaves look like green needles. These needles are shaped like a square. They stay on the tree for many years. When they fall, the twigs feel rough.

Spruce trees have cones. Some cones have seeds with wings. These wings help the seeds move.

People use spruce wood for many things. It makes paper and wood for building. Some trees make pretty Christmas trees.

Native Americans use the roots to weave baskets.

Spruce trees are very useful.

A spruce is a type of evergreen tree.

Most spruces live in the north. They grow in cold regions called the taiga.

You can spot a spruce by its needles. These needles are shaped like a square. Each needle sits on a tiny peg. We call these pegs pulvini.

When the needles fall off, the twigs feel rough. This is because the pegs stay on the branch.

Spruces also have cones. These cones hold seeds with wings. The wings help the seeds fly.

Some spruce trees grow very tall. The Sitka spruce can reach 95 meters.

People use spruce in many ways. The wood is used to make paper. It is also used for building. Some spruce trees make great Christmas trees. Native Americans use spruce roots to weave baskets.

Musicians even use spruce wood for guitars. It helps the music sound good.

A spruce is a special kind of evergreen tree.

These trees belong to a group called Picea. There are about 37 different species in this group. You can find them in the cold northern parts of the world. These areas are called temperate and boreal regions. They are very important for the forests of the Northern Hemisphere. Spruces help make our world beautiful and useful.

Spruces have a very specific way of growing. Their needles are shaped like a square. Each needle sits on a tiny peg called a pulvinus.

When the needles fall off, these pegs stay on the twig. This makes the branches feel very rough to the touch. The needles usually stay on the tree for four to ten years. Spruces also have separate male and female cones on the same tree. These cones hold seeds that have a large wing to help them fly.

Scientists have studied these trees for a long time. Albert Dietrich first set up the genus Picea in 1824. Later, Heinrich Moritz Willkomm looked at the trees in 1887. He studied the parts of the tree instead of just the cones. Other scientists like Heinrich Mayr and Leroy Liu also studied them. Peter A. Schmidt used seed cone shapes to group them in 1989. Even today, scientists use DNA to learn more about them.

Spruce trees come in many different sizes and shapes. The small black spruce grows only 10 to 20 meters tall.

The Sitka spruce is much larger and can reach 95 meters. Some trees can live for a very long time. One Engelmann spruce was reported to be 852 years old. In Sweden, a Norway spruce clone is called "Old Tjikko." This group of trees is thought to be 9,550 years old.

Humans use spruce trees for many different things. The wood is great for building houses and making paper.

Musicians use spruce for the soundboards on acoustic guitars.

This helps the music sound clear and bright. Many people use the Norway spruce as a Christmas tree. Native Americans have used the roots to weave baskets.

Artists have even painted these trees for hundreds of years.

Spruce trees belong to the genus Picea. They are coniferous evergreen trees within the Pinaceae family. There are approximately 37 different species of spruce found in the Northern Hemisphere. These trees thrive in northern temperate and boreal regions, also known as the taiga. Spruces are vital to many ecosystems and human industries. They provide essential timber for construction and pulp for paper production.

Spruces possess unique physical traits that distinguish them from other Pinaceae. Their needles are evergreen and have a square cross-section. Each needle is attached to a small, persistent peg-like structure called a pulvinus. When the needles fall off after four to ten years, these pulvini remain on the twigs. This process leaves the twigs feeling very rough to the touch.

The growth patterns of spruce trees vary by species and age. Young trees often feature a conical crown shape. As they grow older, the shape often shifts into a cylindrical column. Most spruces have straight trunks, though wind or insect damage can cause irregular shapes. Branches grow in regular whorls around the trunk. Young branches typically rise above the horizontal, while older branches grow more level.

Spruce trees are monoecious, meaning they have separate male and female cones on the same tree. The cones contain seeds that possess a large wing for dispersal. The size of these cones varies significantly between species. For example, Picea mariana has cones between 2 and 3.5 cm long. In contrast, Picea abies produces much larger cones reaching 10 to 20 cm. The specific shape and color of the cone scales are key for scientists identifying different species.

Spruces have a very deep history in the fossil record. The Picea lineage began appearing around 130 million years ago. The oldest specific spruce fossils date back to the Early Cretaceous period in western Canada. These fossils are about 136 million years old.

While the lineage is ancient, the modern crown group diverged only about 30 million years ago. This means the biology of modern spruces may differ from their ancient ancestors.

These trees are known for their impressive lifespans. Most spruces live between 100 and 600 years. One recorded Engelmann spruce lived for 852 years. Some spruce groups can exist for much longer through clonal reproduction. A Norway spruce clone in Sweden, named "Old Tjikko," is estimated to be 9,550 years old. This age refers to the clonal group rather than a single individual tree.

Humans have utilized spruce in many ways throughout history. The wood is a standard material for acoustic guitar soundboards. This is because of the specific qualities of the timber.

Native Americans have used the roots of certain species for weaving baskets.

The Norway spruce is also the most common choice for Christmas trees. Even artists have captured their beauty. Augustin Hirschvogel painted them in the 16th century, and Edvard Munch depicted them around 1900.

Modern science uses DNA to study the complex relationships between spruce species. This research often conflicts with older methods based on physical shapes. Scientists look at mitochondrial DNA and chloroplast DNA to map the genus. There is evidence of reticulate evolution, where species hybridize and mix their genes. For example, Picea abies and Picea obovata can create a natural hybrid called Picea × fennica. Understanding these genetic links helps scientists map the entire Pinaceae family.