Italian Alder Native to southern Italy, Alnus cordata is a tall, fast-growing, deciduous tree of conical habit. The flowers appear before the leaves; the yellowish male catkins are long and pendulous, and the reddish female ones much shorter and upright. They are followed by small green cones, larger than those of most alders, which darken and become woody, releasing small winged seeds in autumn and persisting through the winter. The glossy, mid-green leaves are heart-shaped with a finely serrated edge, and stay on the tree as late as December, especially in milder areas. Italian alder is highly wind-resistant and tolerant of even very poor soils, as it is able to fix nitrogen from the air; it will also tolerate pollution and compacted soils, making it a useful urban tree where space permits or reclamation of polluted land. Site: Tolerates exposureSoil: Any soil, including poor, damp and dry soilsPosition: Full sunSeason of Interest: Spring, summer, autumn, winterHardiness: Fully hardyHeight: 82ft (25m) Spread: 26ft (8m)