Strategy for tree and shrub identification

Question

I often find it difficult to identify trees and shrubs even though I have many handbooks and manuals on trees and shrubs in my area (New England). The typical problem is that the species is not in the handbook, or that it is very similar to many other species. For example, hawthorns have many different species which are very similar to each other and most books do not exhaustively list the different hawthorns and their distinguishing characteristics, instead just listing one or two of them.

Web sites are even more fragmented than books and are usually a lot less detailed than the books so even if I search around, the results are often useless.

Am I going about this wrong? What improvements can I make to my strategy for identify trees and shrubs?

Answer 1

Species ID books with pictures, or photos, will generally never be comprehensive enough to include all species, although with some there will be additional information it the text that will give details about other related species, varieties, hybrids or cultivars.

Importantly look for ID books that include an ID key, generally at the start, and learn how to use it. They are usually accompanied with a good explanation of how it works.

The key takes the form of

Does it have this...?

If it does go to [3]

If it doesn't go to [7]

And so on, making successive distinctions until you end up with the species.

They can take some getting the hang of, and you need to know the botanical terms that they refer to.

Also importantly, if you don't already have and use one, you must have a decent hand lense, or magnifying loupe, that you take with you everywhere. Often the deciding features can only be properly be assessed when looking close up, and you need to get to know what the species you are familiar with look like under the lense.

An experienced ecologist friend, an expert in flora and fungi, has a couple of books that have no images in at all, it is just the species ID key, that he takes with him when he is surveying. Granted he already knows his species very well, but you can't remember everything all the time and so you need a book that can tell you the final distinguishing features, even if it is text.

But again a hand lense is a good place to start. My favourite is an Eschenbach 10/40 Pocket hand-held magnifier from Germany http://www.eschenbach.com/cdd40611-ceda-4188-a5c3-882565859296/products-hand-held-magnifiers-pocket-detail.htm

Someone gave this site http://dendro.cnre.vt.edu/dendrology/syllabus/key/key1.cfm?state=&zone= as a good resource for trees in the US