The Latin name for Hazel is Corylus avellana, a part of the Betulaceae. The leaves of the Havel are oval, doubly toothed, hairy and have pointed tips. Before falling in autumn, the leaves turn yellow. Their flowers are monoecious, which means they have male and female flowers on the same tree, however, they must be pollinated by another tree.

Identifying male and female flowers:

male: yellow catkins, appearing before the leaves and hanging in clusters from mid-February 

Female: tiny and bud like with red styles. Once they have been pollinated, they form oval fruits which hang in groups and mature into nuts with a woody shell surrounded by a cup of leafy bracts. 
 
You can find hazel mostly in Europe, North Africa and western Asia. In the UK, they are usually found in lowland oak woodlands.  

https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/hazel/ 
 
Hazel if left without being coppiced, they will grow to 12m and left for 80 years, however when they are coppiced they can live to several hundred years.
Coppicing is a pruning method where the hazel tree is cut to ground level, this encourages the regeneration of new stems from the base. the aim is to rejuvenate the tree and is an ancient woodland

management method. https://heartofenglandforest.org/news/hazel-coppicing-forest