Plants

Alder (Alnus glutinosa)

Common Alder is a native tree in Ireland. It occurs on fens, lakes and marshes often growing alongside willow. It can survive on these sites, which in general lack nitrates, because it has nitrogen-fixing bacteria in its root nodules that extract nitrogen from the air. The male flowers are produced in early spring in long narrow catkins. The female flowers, produced at the same time, are borne in woody, rounded structures resembling tiny pine cones which persist on the tree for more than one season. Pollination and seed dispersal are by wind. The timber of Alder was highly valued due to its durability when exposed to continual wetting and drying. It was used to make sluice gates, canal fittings and clogs. In the furniture trade it was know as 'Irish mahogany'.