This relative of the birches can be found at the northern end of the Autumn Garden, where it is displaying fresh, glossy catkins.
A member of the Betulaceae (birch family) the genus Alnus (alder) contains 35 species of deciduous northern hemisphere trees and shrubs. All species have alternate, simple toothed leaves, and are monoecious, having male and female catkins on the same plant. In all cases the male catkins are longer and are carried in clusters of up to six, while the females, though carried in clusters, are shorter and produce strobiles, or cone-like fruits. Alnus cordata has ovate leaves with a deep basal notch, which resemble a heart, hence the name cordata. Many species of Alnus are associated with moisture, thriving in poor, wet soils, which makes them an ideal choice for land reclamation. This one is of Italian origin and is suitable for drier conditions, and even chalky soils, and can reach 25m in height.