Mine had been growing for a few years Lynn but it wasn't in the best of places, I found the top more tender parts of the foliage died back over winter with it shooting out on the woody stem as far as it got, but the original plant never grew as tall as this one. As mine is in it's second year now and still not flowered I would expect flowers next year so yours might not flower next year. By the looks of the woody stem at the bottom of yours it might have been there last year unnoticed. Your seasons might be longer too so it might flower more quickly.
Mine did withstand the previous to last hard winter which was bad but not as bad as last winter, we had 7 weeks with temperatures below freezing even in the day and down to -17C (about 1F) at night and not much above freezing in the day for some time after. I looked today, there is a bit of a woody stem with a couple of leaves on which looks different to the original plant but the woody stem is broken now at the base, it's in very sandy soil which might help but other Lupins are often not long lived so it's a good idea to grow some more from seed just in case and I guess that one was at it's life end. I'm surprised I didn't have more self sets but I had other ordinary looking Lupins setting around nearby and that plant wasn't too close to my ordinary Lupins so I'm a bit befuddled by that, almost as if the ordinary ones crossed with the tree Lupin if that's possible. I know bees would carry pollen from one to the next assuming two were in flower at the same time but the self sets were close to the tree lupin. I'm really pleased I have one growing again! They might take a few years to germinate or the correct set of temperatures, whichever I'm very pleased, we often don't value a plant so much until we are close to losing it.
I read somwhere that the tree Lupin is hardy to 20F which I think might be right in some soils but in sandy soils plants can often survive to lower temperatures. The yellow one is native to western US in California, wiki says -12C (10F) with them living for up to 7 years.
http://en.wikipedia.org/wiki/L...
They are in Oregon too.. and naturalised in southern England, I'm not far off southern!
http://www.pfaf.org/user/plant...
Aha, I have at least one that looks like the flower on this ID site here, they do cross! I gave one of the self set plants to my neighbour and his is like that too!
http://www.ispot.org.uk/node/3...
I must have been lucky to get one which was the original Lupinus arboreus. Now the question arises Lynn, do you have a Lupin which could be a cross with L. arboreus and had thrown back one like the species?
You guys are awesome. That is it. A bird must have brought it in. Sure was a big surprise when I noticed this tiny little seedling starting up in one of my raised beds that has peonies and Blackberry lilies. I have never seen one of these around here though. Can't wait until next summer when it will hopefully bloom. 
