Alnus subcordata

Caucasian alder is in the birch or Betulaceae family and is native to the Hyrcanian forests of Iran and the Caucasus. It is closely related to Italian alder (A. cordata) and Oriental alder (A. orientalis). It is a fast-growing early pioneer species, growing into a broadly-conical tree reaching up to 25 m tall.

• Leaves are deciduous, alternate, simple, doubly serrated, ovate to oval, up to 15 cm long and 6 cm across, with a short, abrupt point. Petiole is 2.5 cm long. The leathery foliage becomes deep green above, more pale and downy beneath.
• Species is monoecious. Male catkins are drooping and yellow-orange, 8-15 cm long, in clusters of 4 or 5, new ones forming in late summer and lasting over winter. Female catkins are small, red and upright, groups of 2 to 5, 2-3 cm long, becoming green and swollen by mid-summer, brown and woody (non-disintegrating) by winter.
• Bark is pale gray-brown; when bark is removed, stem becomes reddish-orange. Roots are nitrogen-fixing.