I didn't find any Nepeta cataria so I looked at a stem of N. 'Walker's Low'. It has the hairs, so is in line with the ID plant. Having said that, how many other mints might have hairs at the nodes, so not necessarily all that diagnostic I suppose. Picture isn't the best, I tried to get in close with just an iPod, but it does show the "fringe" at the node. I guess if any candidates don't have the hairs it might narrow the field - they seem to be more noticeable at the upper nodes - but one would need an actual specimen to check.
