This alder is displaying its slender catkins alongside the South Walk.
Originating from Iran and Transcaucasia Alnus subcordata (Caucasian alder) has toothed ovate or oval leaves with a rounded or slightly heart-shaped base and a short, abrupt point. One of 25 species of deciduous trees, all of which prefer moist conditions, it grows to form a conical shape to 20m in height. The fissured grey-brown bark provides interest year-round, but it is the male catkins hanging in groups of four or five to 15cm in length which are of note during winter.