Hi Pete, *waves*
As discussed, the ID of Lime trees - Tilia - is really difficult as they hybridise so freely. The books say that there are three main types: Common, Large leaved, and Small leaved, with Common being a hybrid of the other two. Plus a few more ornamental varieties, but I don't worry too much about those as they are not likely to be found outside of parks and aboretums. Arboreta? You know what I mean.Oh, and disregard the phrases "large leaved" and "small leaved" as the size of the leaves is NO sort of indicator, annoyingly!
Be warned, they continue to hybridise, so there are in fact a wide range of hybrids, all shading from closer to one, than the other. So they don't always fall neatly into their category.
Having said all that, I made a crib, or Table of Differences, for Limes last year (or was it the year before?) which now seems a bit basic, but it might get you started on creating your own crib:
As you can see, very simple: it's not a key, simply a collection of relevant ID points all in one place, for the three main Limes plus the one that I've encountered locally - of course, you are most welcome to add as many other species as you wish, I restrict mine to commonly occurring species, in order to keep them down to A6 size for my famous Botany Cribs pack (which certain members of the Midweek Botany Crew keep trying to steal). They usually start out hand written, but after an Incident on a rainy day, I decided to copy them all onto spreadsheet format, so that I had a permanent copy at home.
This has proved to be a very good way of doing it: I print them out and stick them onto the index cards, I can then annotate while out in the field, then at home I update and reprint every so often. And when they get too wet to read, I just print off new ones.
Here's my battered pack:
Hope this gets you started - the idea is that you fill in any gaps, and add more features as you discover them. Obviously I don't bother with any features that they all share, just in features that help to differentiate.
When you come across a tree that doesn't quite fit any of the categories, then you have to turn to the reference books, but at least the crib can cut down the number of times you need to do that.
Have fun!
