Alnus are vigorous deciduous trees or large shrubs with rounded leaves and notable catkins in winter. Glutinosa is a deciduous tree to 25m, conical and broad when young, with rounded green foliage and grey-purple buds. Long, reddish-brown catkins appear in winter. An ideal habitat for wildlife, insects and fungi. Fully hardy, it will tolerate most coastal sites and wet soils but well-drained soil is preferable.