There are thousands of different tree species, hybrids, cultivars and varieties in the UK. However, according to some sources there are only 33 that are UK natives.

'Native' trees are defined as those that were able to migrate from mainland Europe without the aid of man. The period in which this refers to is after the ice age (9-10,000 years ago) and before the land connection with the continent was eroded, approximately 5,000 years ago.

There are a large number of trees that have been introduced since that period which have colonised very well and are termed as 'exotic' species.

Native Trees are highlighted. 

Alder (Alnus spp) – General, Common, Grey
Ash (Fraxinus excelsior)
Beech(Fagus sylvatica)
Birch (Betula spp) – Silver, Downy
Blackthorn (Prunus spinosa)
Cherries (Prunus spp) – Bird, Wild/Gean
Crab Apple (Malus sylvestris)
Dog Rose (Rosa canina)
European Larch (Larix decidua)
Guelder Rose (Viburnum opulus)
Hawthorn (Crataegus spp) – Common, Midland
Hazel (Corylus avellana)
Holly (Ilex aquifolium)
Lime (Tilia spp) – Large Leaved, Small Leaved
Maple (Acer spp) – Field
Oak (Quercus spp) – English, Sessile, Holm
Pine (Pinus spp) – Scots
Rowan (Sorbus aucuparia)
Sycamore (Acer pseudoplatanus)
Willows (Salix spp) – Goat, Bay, Crack, White, Weeping
Yew (Taxus baccata)