Hazel - Corylus Avellana

I found this Hazel tree (the latin name for which is Corylus Avellana) within Longford Park. There were grey skies and the multi-stemmed shrub appeared to be recieving no nourishment from sunlight or rain. This particular Hazel tree has both male and female catkins. The male catkins are short and green when they first appear in August. However, having found this tree early spring, they are fully grown (up to 8cm) and yellow. The female catkins are red and very small as you can see below.
Information from Collins Complete Guide to British Trees