Fuzzy matching a tree structure

I'm looking for a good way to do fuzzy matching of a tree against a family of trees.

I know how to look for an exact match between two trees. Just do simultaneous traversals down both of them and see if they're the same.

Now, I would like to (1) quickly match against multiple trees, perhaps on the order of thousands of trees; and (2) do a fuzzy match (for example, severals leaf nodes may be mismatched, but that's ok).

For an exact match against multiple trees, I could hash each tree. But the fuzzy match against multiple trees seems difficult. Any ideas?

>>7

more efficient and flexible
Efficient yes, flexible- what the fuck are you smoking? To make that flexible at all you would need to completely rewrite it into much the manner than fuzzy string matching is done. It accounts absolutely NOTHING for ordering or structure. Are you telling me the tree:
            b
    a                r
t        n        o        a
is exactly the same as the tree:
            a
    n                r
t        a        b        o
or that the following tree is more similar:
            b
    a                r
t        n        e        a

And anyway, your other arguments are pretty much invalid too. It is certainly not more effecient to try and write a complex fuzzy matching algorithm from scratch than to use an existing peice of code. In terms of speed... well; I just tested on java and the time taken to serialize a tree is actually less than the time taken to iterate over a tree and store a reference to each node in a lookup table.