Too bad I missed this one on my prickly day last month. It's in 3AAF, behind the Admin building just before getting to the Tetradium. We were excited by one stem of it, and then we noticed that there is really quite a lot of it. As I was typing this, I came across some photos on flickr of Rubus alceifolius (several photos there), which is on the list in that area. Is that what this is? Other google photos of that species don't match this garden plant nearly as well as that excellent group of photos on flickr.
Yes, Wendy this is Rubus alceifolius. It's quite vigorous, there is probably a label stake about a metre into the mass, that it has grown past. I have never seen any flowers or fruit on it. Which is probably a good thing, since it is so invasive in warmer areas.
Thanks, Eric. I was going to offer to eat any fruits we find next year, but I just remembered all those thorns. We were sure there was a label in there somewhere, but we weren't up to getting in there to look for it.