Boxelder Maple - Acer Negundo

The Boxelder Maple (Acer negundo) is a maple tree species native to a broad area that stretches from south central Canada down to Texas and parts of Mexico and as far east as New York and Florida. It is a small to medium sized tree with gray bark that forms ridges that grow more pronounced with age. One distinctive feature of this tree species is its pinnately compound leaves that usually have five leaflets but can also have three or seven as well. Some of the leaflets have a tendency to be asymmetrical as can be seen in the image below.

The seeds of the Boxelder maple grow in long racemes of "Samaras" (winged seeds). These clusters of paired seeds are green while they grow turning light brown when mature. This is one of the characteristics that makes this tree an interesting ornamental tree for urban environments.

Detail of the paired samaras. You can see that they are slightly offset.
The picture below illustrates how the racemes of samaras grow along the undersides of the branches.
Of special interest for ornamental uses is the variegated version of this tree species. As can be seen in the picture below the variegated trees have very interesting patterns of greens and light creamy white colors on both the leaves and the samaras.
This maple tree species is widely used in Spain as an urban tree for parks and avenues. Maple tree species that are native to Spain is the Montpellier Maple and the Sycamore Maple.

A common Maple tree species in Eastern North America is the Red Maple - Acer rubrum.

Another interesting tree with variegated leaves is the Schefflera arboricola.

Another tree with pinnately compound leaves is the Coral tree.