Buds and catkins are the sexual part of a tree and are very important for sexual reproduction .Buds are a collection of cells where flowers or leaves grow from. They are also important features on trees to help us identify the tree. The above picture is of a bud on a Ash tree (Fraxinus excelsior)
This is a catkin and they differ from buds because they are unisexual and are pollinated by wind or sometimes by insects. This catkin is from a Crack Willow (Salix fragilis).
