Tree Ferns like Lepidodendron make up the bulk of our coal seams laid down in the carboniferous period about 300 million years ago. Angiosperms - Flowering Plants and more modern types of tree started coming in during the cretaceous about 130 million years ago.

Fossil angiosperms are quite common in Tertiary rocks of SE England (Tertiary period started about 60 million years ago). As a good pointer for northern Europe it's worth bearing in mind that most of the fossil amber you see around the place comes from Tertiary rocks in the Baltic, roughly between 25 - 55 million years old. Amber, of course, is the fossilized resin from coniferous trees like pines.