Hazel catkins

The hazel is a monoecious tree, meaning it has separate male and female parts on the same tree with male flowers on hanging catkins and tiny female bud-like flowers with red stigmas
The male flowers are on yellow catkins that hang down ready to release pollen onto the wind. There may be over 200 unisexual male flowers on a single catkin.
Each maleflower is covered by a scale which lifts when the catkin is ready to release pollen. Underneath each scale there are 4 pairs of green stamens full of pollen. The stamens split open to release pollen for wind dispersal when the conditions are suitable.
Each female flower bud has several flowers. Each flower has 4 stigmas to collect pollen. If fertilised, each flower will produce one nut, known as a cob.
One to four nuts are produced from one bud, depending on how many flowers were fertilised.
Although the catkins are forming now it won't be until later on in the spring when they release the pollen and when the female flowers will be ready.