Common Alder

This is a deciduous tree with an upright habit of growth usually found on poor wet soils. It has dark green leaves 4 inches long. Groups of 3 to 5 pendent yellow brown male catkins 4 inches long are produced in late winter or early spring. It bears ovoid fruits, a half to three quarter inches long, in summer. It can grow to a height of 80 feet with a width of 30 feet.

The two common modern trees, which were uncommon 8,500 years ago, are the Alder (Alnus glutinosa) and the Ash. The Alder expanded its population in many parts of Europe just after 8,000 years ago. It had arrived in Ireland somewhat earlier but seemed to have been held in check. The changes which occurred to give it a competitive edge advantage after 8,000 years are not clear, but its present habitat in damp places and river banks suggest that a change to a moister climate may have been responsible for its increase.

This tree has been successfully used to create a screen between residential developments and industrial units on poor heavy wet soils. It is also an attractive tree singly or in groups in parkland or in large gardens sloping down to a lake, lagoon or river.