Catkin
A catkin or ament is a slim, cylindrical flower cluster, with inconspicuous or no petals, usually wind-pollinated but sometimes insect-pollinated. It contains many, usually unisexual flowers, arranged closely along a central stem that is often drooping. Catkins are found in many plant families, including Betulaceae, Fagaceae, Moraceae, and Salicaceae.
Occurrence
Catkin-bearing plants include many trees or shrubs such as birch, willow, aspen, hickory, sweet chestnut, and sweetfern.In many of these plants, only the male flowers form catkins, and the female flowers are single, a cone, or other types. Corylus jacquemontii has male catkins and also female spikes.
In other plants, both male and female flowers are borne in catkins. Populus alba has male catkins which are grey and the female catkins are greyish-green.
While the blooming months for catkins may vary due to factors such as climate change and latitude, the following are some general timeframes: Hazel catkins bloom from January to March, alder catkins from February to March, silver birch catkins from March to May, oak catkins from April to May, and white willow catkins from April to May.
In Britain, catkins can be seen in January or February, when many trees are bare for winter. They can even occur in December.