Trees to look for in August — Birch Tree

There are two main native British species of birch tree – Silver Birch (Betula pendula) and Downy Birch (Betula pubescens). They are wind pollinated and have separate male and female flowers (catkins) on the same branch. Male catkins develop during the autumn and are covered by reddish brown scales, while female catkins are held upright on the twigs and are made up of overlapping green scales. Fertilised female catkins look a little like a cone and slowly break up in autumn to release wind dispersed winged fruit. The fruit and seeds are tiny (about 2 mm) and are produced in huge quantities!

 

It can be tricky to tell the difference between the types of birch as they will easily breed with each other (hybridise). The main way of telling them apart is by their bark. Silver birch has whiter, more papery bark than downy birch, which varies from silver-grey to brown. On old silver birch trees, knobbly black bark replaces the white bark at the base of the trunk. Silver birches have weeping (hanging) smooth twigs while those of downy birch are covered with short fine hairs.

For more info see https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/downy-birch/
https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/silver-birch/