Trees are large plants. The main parts of plants can be easily identified when looking at them: their roots, their stems or trunks, and their leaves are all clearly visible. Trees use their sturdy roots to attach themselves into the ground. Their stems grow upwards towards light, and their leaves produce energy from this light through a process known as photosynthesis. Because cities have usually been built on locations with good climate conditions, many kinds of tree species thrive in them. Various kinds of broad-leaf tree species can be found in parks, for example. 

The oak (species 1 in the image below) is one of the most magnificent trees in European parks. It is known for its acorns, which are used as food by squirrels and birds. Wood from oak trees can be used to produce furniture and flooring.

The leaves of a maple tree (2) is easily recognizable. During the autumn, the leaves of the maple tree change into a deep red color, as the maple collects all of the valuable chloroplasts into its trunk when preparing to drop its leaves for the winter.

The lime tree (3) is a common park tree. It can be recognized from its heart-shaped leaves.

The ash tree (4) is a relatively rare park tree. Its leaves consist of leaflet pairs. The elm tree (5) can be recognized by looking at its sharp, dark leaves.

Some trees, such as birches and alders, are wind-pollinated. This means that their pollen grains are transported from one tree to another by the wind. To make sure this happens, wind-pollinated trees produce large quantities of pollen during the spring. This can cause problems for people with pollen allergies. As a result, birch and alder trees are not usually grown in cities or in parks. 

Coniferous trees are also often found growing in parks. They do not reproduce via flowers. The most common coniferous trees are the pine and the spruce. Most coniferous trees are evergreen, which means that they do not drop their leaves for the winter.


Park trees. 1. Oak, 2. Maple, 3. Lime, 4. Ash, 5. Elm.