The leaves are alternate,
round, and 2.5-6 cm long. They are hairless, dark green on the upper
surface and paler on the underside with a coarsely blunt-toothed margin.
They have strongly flattened stalks, as long as, or longer than the
leaves, which catch even the slightest breeze, causing a trembling movement
and a rustling sound.
Aspen is a deciduous
tree up to 20m in height. Sometimes it has a single silvery-barked
trunk strongly marked with black diamonds, but in exposed places or
on poor soils, it is often also a shrub with many suckers.
It grows in open woodland, generally on moist soils with little lime
The leaves on
the suckers are larger, maybe 5-12
cm long. They are sharply pointed and slightly hairy.
The male and female
catkins are 5-8 cm long and appear
on separate trees (dioecious)
in February and March, before the leaves.
The brown male
catkins have reddish-purple anthers.
The green female catkins have pinkish
or purplish stigmas, divided into
two or more lobes.
The leaves are
food for the caterpillars of the green hairstreak butterfly.
The wood can
be used to make matches.
lived on Scottish rivers, aspen was one of their main food sources.