Alnus Glutinosa

Alder (Alnus glutinosa)

Alnus glutinosa was originally planted in Milton Keynes but could not stand up to the harsh clay soil therefore most of the Alder found in the City is Italian Alder (Alnus cordata) and Grey Alder (Alnus incana) both of which tolerate pollution and dry soil.

Family – Betulacae.

Description – Rapidly growing tree (0.5m pa for the first 30-40 years), mature at about 60 years with long trunk and narrow crown. Distinctive outline in winter. Requires plenty of light and can be used as pioneer species.

Height – 20m or more (in ideal conditions).

Age – up to 150 years.

Habitat - Very tolerant of water logged conditions whilst dormant. Typical streamside tree and will grow on relatively infertile soils and hence used for site reclamation.

Timber - Light reddish brown and porous with course texture.

Bark – Grey, smooth, then brown-black. Bleeds’ orange-red if damaged.

Twig – Sticky (glutinous) green then purple-brown and glabrous.

Buds – Stalked, erect, narrowed at the base, flattened, with 2-3 green/purple scales.

Fruit – Cone-like, hard, green then brown. Persist long after winged seeds have dispersed.

Leaf – Initially sticky then glabrous except for the vein-axil creamy hair tufts below. Widest at or above the middle. Blunt end, midrib often ends in a notch. 6-7 paler veins each side. Wavy margin. Broad wedge-shaped base. Petiole with raised lenticels. Dark green/black in autumn.

The Tree Year Flowers - February / March Leaves - April Fruit - October / December Ripen - December Leaves fall - November

Uses - General purpose hardwood and pulpwood. Particularly suitable for turning, formerly used to make clogs. Burns quickly when used for firewood but suitable for charcoal (used to be used for charcoal in gunpowder). Hardens when immersed in water and suitable for making piles.

Food and Drink - The bark and leaves contain tannin and have astringent properties. Used in folk medicine to treat chills.