Aspen facts for kids

Aspens are special trees that are part of the poplar family. Their leaves shake and 'tremble' even with a tiny breeze. This is why they are often called 'trembling aspens' or 'quaking aspens'. There are two main types of aspen trees.

American Aspen Trees

The American aspen, known scientifically as Populus tremuloides, grows in cooler parts of North America. These trees are quite unique.

They often grow in huge groups that are all clones of each other. This means they are genetically identical. These groups are connected by one big root system hidden underground. New trees sprout up from the roots of an older 'parent' tree.

The most famous example is a giant grove in Utah called 'Pando'. Some experts believe Pando is the largest living thing on Earth by weight or size. It covers an area about the size of 106 football fields. It is estimated to weigh around 6,600 tons!

European Aspen Trees

The European aspen, or Populus tremula, is found in cool areas of Europe and Asia. You can find it from the British Isles all the way to Kamchatka in the east. It also grows north into the Arctic Circle and south into places like Spain and Japan. There's even one spot in Algeria, Africa, where it grows. In warmer areas, it prefers to grow high up in mountains.

This tree is very tough and can handle long, cold winters and short summers. Unlike most trees, where male and female flowers grow on the same tree, aspens are 'dioecious'. This means each individual aspen tree is either male or female.

Aspen trees flower in March and April, before their leaves appear. Both male and female trees produce special flower clusters called catkins. After pollination, the female catkins ripen in early summer. They then release tiny seeds that have fluffy hairs, helping them float away.

Like other aspens, the European aspen mostly reproduces by growing new trees from its roots. These root sprouts can pop up as far as 40 meters away from the main tree. This creates large groups of genetically identical trees, just like the American aspen. Many new shoots can grow this way, especially after big events like a forest fire.

Images for kids

• 

  Populus tremuloides

• 

  Individual clonal stands can be seen during the autumn, as on this mountainside in the Matanuska Valley in Alaska.

• 

  P. tremuloides leaves on mature trees are nearly round, 4–8 centimetres (1.6–3.1 in) in diameter with small rounded teeth, and a 3–7 centimetres (1.2–2.8 in) long, flattened petiole.

• 

  P. tremula leaves: adult (left) and juvenile (right)

• 

  American aspens, Populus tremuloides

• 

  Aspen seedlings in a nursery

• 

  Leaf of Populus grandidentata.

• 

  Autumn colour of Populus tremula.

• 

  Male flowers (catkin) of Populus tremula.

• 

  Aspen grove in fall.