Grey alder – Alnus incana

Deciduous tree or large shrub.

3–20 m high.

The tree has a single bole or multiple boles. The trunk is slender. The cortex is gray and smooth. The young branches and buds are pubescent and dry.

The leaf arrangement is spiral. The lamina is 2.5–9 cm long, elliptic to roundish, attenuate or rounded at the base, acute at the apex, simple, double-serrate. The nodes of the veins are glabrous on the abaxial side. The winter buds are distinctly spurred and 4–6 mm long.

The tree is monoecious and flowers before budding of leaves. The inflorescence is a catkin which consists of numerous small two- or three-flowered cymules. The flowers are unisexual, small, achlamydeous or nearly so. Staminate and pistillate flowers are in separate catkins.

The fruits are small, flat, winged achenes that matures inside female catkins which become hard, lignified, dark-brown “cones”. The “cone” at the summit of a twig is short-pedunculate and the rest are sessile.