Alnus cordata

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Alnus cordata
Italian Alder foliage and immature male catkins
Italian Alder foliage and
immature male catkins
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Fagales
Family: Betulaceae
Genus: Alnus
Subgenus: Alnus
Species: A. cordata
Binomial name
Alnus cordata
Desf.

Alnus cordata (Italian Alder) is an alder native to southern Italy (including Sardinia) and Corsica.

It is a medium-sized tree growing to 17–25 m tall (exceptionally to 28 m), with a trunk up to 70–100 cm diameter. The leaves are deciduous but with a very long season in leaf, from April to December in the Northern Hemisphere; they are alternate, cordate (heart-shaped), rich glossy green, 5–12 cm long, with a finely serrated margin.

Italian Alder mature female (seed) catkins
Italian Alder mature female (seed) catkins

The slender cylindrical male catkins are pendulous, yellowish in colour and 5–10 cm long; pollination is in early spring, before the leaves emerge. The female catkins are ovoid, when mature in autumn 2–3 cm long and 1.5–2 cm broad, dark green to brown in colour, hard, woody, and superficially similar to some conifer cones. The small winged seeds disperse through the winter, leaving the old woody, blackish 'cones' on the tree for up to a year after.

Like other alders, it is able to fix nitrogen from the air. It thrives on much drier soils than most other alders, and grows rapidly even under very unfavourable circumstances, which renders it extremely valuable for landscape planting on difficult sites such as mining spoil heaps and heavily compacted urban sites.