Alnus glutinosa
This is also called the Black Alder or Howler. A native tree, it has been with us a long time. It has grown in Britain beside water since the last glaciers retreated. The alderwoods or `carrs’ as they are known in Norfolk don’t give a true impression of the tree. The gnarled specimens beside torrents in Scottish glens are the most impressive, Usually growing up to 30 or 40 ft., they can reach 80 ft. as in Sandling Park in Kent. There are some vast forests in Russia with some reaching 100 ft.
It is nearly always found beside water where it can grow in places where willow cannot. This is because it enriches the soil with its root nodules as well as stabilising the bank. When grown on porous soil it only forms a bush, which might explain why it is planted on motorway verges.
The wood is interesting. When cut it bleeds a reddish colour: this was enough to make our forebears nervous about using it. Recently we have been less squeamish. The wood is waterproof and shock-absorbent, which might explain why it was used on the ancient trackways across the wetlands in Somerset and more recently to provide the piles on which Venice is built. It is also a light wood, easy to turn and a poor conductor, explaining why clogs and cigar boxes were made from it.When felled the wood is white then reddish and after seasoning turns a pinkish yellow.. More unusually the leaves were used to relieve tired feet, and a black dye was extracted from the bark.
It has a dearth of branching, rather like a pine, making for a good winter silhouette. The specimen in the Park is beside the Cafe and our photograph was taken in deep winter. It is easily recognised then by its false `cones’ and in the summer by its leaves, which have a small notch at the end.
The `cones’ are female catkins which are oval, green fruits earlier in the year and which shed floating seeds. The male catkins are long and an unusual purple colour.They are produced before the leaves in February and March. This photograph was taken about four years ago and the tree seems to be doing well. They can grow 40 ft, in 20 years, but recent reports suggest there may be a disease affecting alders, spreading like Dutch elm disease; hopefully ours will be safe.
Redpolls and siskins can occasionally be seen searching the `cones’ for seeds during the coldest periods of winter.