Alnus maximowiczii (which appears to have no common name) is one of the green alders and used to be listed as Alnus viridis subsp. Maximowiczii. It is a small tree, growing to 9 to 12m high and is often multi-stemmed as in the example in Belfast Botanic Gardens. The leaves are larger than those of our native alder and the tree casts a dense shade in summer. The male and female flowers are separate, but may often appear close together on the same branch. The male flowers are long yellowish catkins and the female flowers are a short cylindrical structure with red stigmas. The female cones develop into an ovate shape and remain on the tree long after the seeds have been shed. They are very similar to the cones of the native Alnus glutinosa and quickly show to what genus this tree belongs. Alnus maximowiczii is native to the Russian far east, Japan, Korea and the extinct volcanic island of Ullong Do between Japan and Korea. It seems to be rare in cultivation but is listed by two UK specialist nurseries.

Photos taken in Belfast Botanic Gardens in 2011. Copyright: Friends of Belfast Botanic Gardens