Ulmus davidiana

The David elm is a small tree. It grows in many lands. It lives near streams and wet ground. This tree can grow quite tall. It makes thick shade for us.

The leaves feel a bit rough. The bark stays smooth for a long time. Then the bark gets cracks.

This tree has small flowers. The wind helps move them. In the spring, it grows small fruit.

Some trees do very well in wet soil. They can even survive a hard freeze. This makes them strong trees. It is a very special tree.

The David elm is a small tree. It is named for Armand David. He was a man who studied nature. This tree grows in many places. You can find it in China and Japan. It also grows in Korea and Mongolia.

These trees like to live near streams. They grow well in wet soil. The tree can grow 15 meters tall. It has a thick canopy of leaves. This makes heavy shade. The bark stays smooth for a long time. Later, the bark gets long cracks.

In March, the tree grows small flowers. The wind helps move the pollen. After that, it makes small fruit. These fruits are called samarae.

Scientists study this tree in the United States. It may be a good tree for lawns. It can survive a hard freeze. Some leaves stayed alive during a five-day freeze. It also resists some tree diseases. This makes it a very strong tree.

The David elm is a special kind of small tree. It is known by many names, like the Father David elm. This tree is a deciduous tree, which means it loses its leaves each year. You can find these trees in many parts of Asia. They grow in China, Mongolia, Korea, Siberia, and Japan. Most of them live near streams in wet areas. They like to grow at high elevations between 2000 and 2300 meters.

Watching this tree grow is quite interesting. It can reach a maximum height of 15 meters. The trunk is usually quite slender, staying under 0.3 meters wide. As the tree gets older, its bark changes. It stays smooth for a long time before it develops long cracks. The leaves are shaped like an oval with a wider top. The top side of each leaf feels rough to the touch.

In the month of March, the tree starts its yearly cycle. It grows small flowers on shoots that are one year old. These flowers do not have petals, so they are called apetalous. The wind helps move the pollen from flower to flower. After the flowers, the tree grows small fruits called samarae. These fruits are less than 19 millimeters long.

People have studied this tree for a long time. A naturalist named Armand David collected specimens in the 1800s. He was a French missionary who introduced the tree to France. Scientists first described the tree in 1873 near Beijing, China. Later, in 1916, experts at the Arnold Arboretum described two different species. There has been much talk about whether the Japanese elm is a separate species or a variety.

This tree is very useful for people who plant gardens. At the Morton Arboretum in Illinois, researchers found it resists Dutch elm disease. It also resists the elm leaf beetle and elm yellows. Scientists at Ohio State University tested it in different soils. They found it can grow well in wet soil and alkaline soil. In 2007, many leaves survived a hard five-day freeze. This shows the tree is very tough and strong.

The David elm, scientifically named *Ulmus davidiana*, is a small deciduous tree. This means it sheds its leaves every year. It is a significant species because of its resilience and unique growth habits. This tree is widely distributed across several Asian regions. You can find it in China, Mongolia, Korea, Siberia, and Japan. It often grows in wetlands near streams. These trees typically thrive at high elevations between 2000 and 2300 meters.

Physically, the David elm has several distinct characteristics. It can reach a maximum height of 15 meters. The trunk is relatively slender, usually measuring less than 0.3 meters in diameter. This slender trunk supports a dense canopy that casts heavy shade. The bark remains smooth for a long time during the tree's life. Eventually, the bark becomes longitudinally fissured, which means it develops long cracks. The leaves are obovate, meaning they are shaped like an egg with the wider end at the tip. These leaves are less than 10 centimeters long and 5 centimeters wide. The upper surface of each leaf feels rough to the touch.

The reproductive cycle of the David elm follows a specific seasonal pattern. In March, the tree produces flowers on shoots that are in their second year. These flowers are apetalous, which means they lack petals. They are also perfect flowers and are wind-pollinated. After pollination, the tree develops fruit known as samarae. These samarae are less than 19 millimeters long and 14 millimeters wide. This process ensures the tree can spread its seeds through the environment.

Botanists recognize two main varieties of this tree. The first is *Ulmus davidiana* var. *davidiana*, which occurs only in China. The second is *Ulmus davidiana* var. *japonica*, known as the Japanese Elm. This second variety has a much wider range. There is some scientific debate regarding this classification. Some authorities do not consider *japonica* to be a variety. For example, the *Illustrated Flora of the Primorsky Territory* maintains *Ulmus japonica* as its own separate species. In 1916, the Arnold Arboretum also described them as two different species.

The history of the David elm is tied to the naturalist Armand David. He was a French missionary who collected specimens in the 19th century. Because of his work, the tree is often called the Father David elm. The species was first described in 1873 from the hills north of Beijing, China. Later, in 1916, Charles Sprague Sargent published an enumeration of woody plants collected in western China. This helped document the tree for the Arnold Arboretum of Harvard University. These historical collections helped scientists understand the tree's true identity.

Research has shown that the David elm possesses remarkable biological strengths. At the Morton Arboretum in Illinois, the tree showed good resistance to Dutch elm disease (DED). It is also reputed to resist the elm leaf beetle, elm yellows, and leafminers in the United States. Testing at Ohio State University provided more specific data. Researchers found the tree can perform well on disturbed sites and in calciferous, or alkaline, soils. It also shows a better tolerance for wet soil than previously thought. During a hard freeze in April 2007, at least 50% of emerging leaves survived. This freeze lasted for five days, and temperatures dropped to −6°C (21°F).

Because of these traits, the David elm is a subject of interest for cultivation. A nursery called Hillier & Sons briefly marketed the tree between 1971 and 1977. During that time, they sold only four trees. While there are no known cultivars, the tree shows promise for landscape use. Some saplings have been pruned to improve their structural stability. This helps create a more stable branching pattern as the tree grows. Today, the tree is held in many botanical collections around the world, from the Chicago Botanic Garden to the Royal Botanic Garden Edinburgh.