Beech (Fagus sylvatica) is a large tree native to southern England/Wales but has since spread across the country. It grows best on limestone/chalky soils and if coppiced, (see February), can live up to a thousand years! Beech is wind pollinated and has separate male and female flowers on the same branch. Once pollinated, they develop into spiny, woody husks which normally hold two, 3-sided nuts (called mast). The mast are carried away by birds and other animals such as mice.
This month the leaves will be forming a dense summer canopy. The edges of the leaves are wavy and when they first appear, have small hairs on the margin and underside, but these are lost as the leaf gets older. The soft, young leaves open by April and are a pale and vibrant green which toughens and darkens with age. The leaves are tougher on trees growing in the open and more delicate when growing in woods and they can even twist on their stalks to face the sun!
For more info see https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/common-beech/