Alnus species - Alder

There are three common varieties of Alder in VC77.

Alnus glutinosa, Alder, is by far the commonest. It favours wet ground and river banks but is also widely planted.

The bark is fissured. Buds are stalkless and purple (diagnostic). The leaves are toothed, about as long as broad, flat-ended or with a shallow notch at the tip. Leaves are hairless except for a few hairs underneath in the axils of veins, and are on glabrous twigs which have stalked side-buds. The male catkins are long and the fruits (cones) are persisting and woody.

Alnus incana, Grey Alder, is commonly planted in parks and roadsides. The bark is smooth and the twigs pubescent. The leaves are greyish underneath, broad, toothed and come to a point.

Alnus cordata, Italian Alder, is unlike the other Alders except for the fruit (cones). The leaves are dark glossy green, obviously heart-shaped (cordate), with lots of small, shallow, forward-pointing teeth. Underneath, the leaves have large tufts of orange hairs in the vein axils and long hairs flat on each side of the midrib.