The alder is a genus of trees and sometimes shrubs common to most of the northern temperate zone. The Latin name for this genus is Alnus. It is very commonly, but not exclusively, found in riparian areas. That is, by stream sides.

The alder is a member of the Birch Family and of the Willow Order, or Betulacaea and Sales in Latin. It has much in common with its cousins, namely: no edible fruit, production of many tiny seeds from small flowers, seperation of male and female flowers, small stature if conditions dictate, and a penchant for cold and wet climates. Of course, all of these are tendancies and not rules.

One of the unique things about the alder that seperates it from it's contemporaries is it's ability to fix nitrogen, a property usually reserved to plants in the Legume order. Of course, it is not the tree itself, but bacteria in nodules the roots that do the actual fixating, but the trees are still neccesary for the process.

Another interesting thing about the alder is that it is the only angiosperm to produce cones, or at least structures that superficially resemble them. The female flowers of alder species develop into a structure that looks a great deal like a small pinecone. The male flowers are hung by the dozens off of a small structure looking somewhat like a caterpillar and called a catkin.

Although I said earlier that most members of the Birch family don't have edible fruit, the catkins of the alder tree are edible, although not very tasty. They are much more appeatizing then they look, and if you are lost in the woods, eating a cupful of them is very tasty indeed.