- Alnus glutinosa
Alder is a common tree along watercourses, damp ditches and other wet habitats. The male catkins are superficially similar to those of hazel, but rather more reddish. The long male catkins produce the pollen, which is carried on the wind to the smaller, red female flowers seen above them (which are not reminiscent of hazel). After pollination these female flowers develop into small, woody cone-like fruits which persist on the branches for some time, which makes alders easy to recognise and identify!