The other day I wrote about the charming, yellow birds – siskins. You may remember that the siskin’s favourite food is the seeds of an alder tree and, wanting to know more about the alder, I’ve dedicated today’s article to it.
The alder is one of those magical-looking trees, well suited to a fairy tale or fantasy landscape scene. They like to live in damp places so are most often found alongside rivers or in swampy ground. They are very fast growing plants and can get as tall as 20 metres in height – that’s one big tree!
The bark of an alder is often cracked and covered in lichen, which all adds to its magical appearance. Their leaves are rounded in appearance with saw-toothed edges and their flowers (which start appearing about this time of year) are yellow and green. The yellow flowers are male and the green female. These are pollinated, with the help of the wind, and then develop into cone-like fruits on catkins – the siskin’s favourite delicacy.
In addition to providing food for siskins and other small birds (and caterpillars with its leaves), the alder benefits its environment in other ways. It has a symbiotic relationship with a type of bacteria which lives on its roots. The bacterium takes nitrogen from the air and gives it to the tree, which gives sugars in exchange. As well as helping the two species, this process makes the soil more fertile which helps plants.
Did you know that we get a certain dye from the alder tree? It’s a green colour which was worn by medieval outlaws (think Robin Hood) and was associated with woodland fairies. Its wood has a particularly magical property – it turns red after being cut. This gave rise to the superstition that the tree bleeds, which of course it doesn’t. Nevertheless, some people are wary of the alder and careful if they pass one. Fancy that – being scared of a tree!