Does "1 kaffir lime leaf" mean a pair of leaves, or half a pair?

I love kaffir lime leaves. In fact, I bought a kaffir lime tree so that I can have them all the time without making a grocery run. The leaves look like this:

I have some very nice recipes that call for them but even my French/Cambodian cookbook with the amazing illustrated ingredient encyclopedia does not clear up one thing:

Is that three leaves or six?

I'm in the middle of making a paste right now that calls for "5 kaffir lime leaves" and so, according to my usual habit, I'm going to go and pluck 5 leaves off the tree... Which means, I'll have 10 leaf segments. Or will I have 10 leaves?

The taste is so nice that I've never had the feeling I was doubling the amount called for. Still, I'm curious—is there some widespread agreement, or even better, an authoritative source regarding what is "1 leaf?"