Identify tree found in woodland of VT

I have lived in Vermont all my life and never seen this plant.  Just this summer, this plant popped up on the property. 

It has grown fast and is better than 10 feet tall and still growing.  It has big opposite leaves growing out of the stock (which seems to be bamboo like) and yet the purple/blue blossoms on the top are very compact and dainty. 

Any Idea what it may be?

Thanks,
Stacie

Looks to me like it is in the dandelion family.

The blossoms look more like Ironweed,  but this has a single stem/trunk and is 10 feet tall with a different leaf structure.

Does it have any woody parts? It doesn't look like a tree to me.

No it doesn't.  The stock is more like bamboo: green, no ridges.  2 inch diameter at the base. I have walked our property and have not seen any others like it.  Very interested in finding out if it is invasive.
Thanks,
Stacie

We have plants similar to this growing on the central coast of California.  Some are more close to dandelion in appearance and others like yours aren't because they have "branches" and many flowers.  I've seen plants looking almost identical to this but not exactly.  The blue flower petals are new to me. I think all the ones I have seen were white, yellow or red.  Because yours is so tall I am pretty sure it has to be in the Asteraceae family (sunflower).  Read this page and maybe it will synch up for you:

http://en.wikipedia.org/wiki/Asteraceae

As a side note, the Carrizo Plain in California has a wide variety of Asteraceae growing. Some are close to the ground whereas some look more like the traditional sunflower but with many flowers that are half the size or 1/4 the size of normal sunflowers.  I think even lettuce is in the same family, its a big family and there's a lot of variation.

I will research the possibility of this being of the sunfower family.  This is curious to me.  This year is the first year I planted sunfowers on the property!! 
Thanks for the info.  I will let you know what I come up with. 

Stacie

I agree, it certainly looks like a member of the Asteraceae, and if I had to guess, I'd put in the genus Lactuca, which would make it a close relative of lettuce. Perhaps Lactuca canadensis? Have a look here: http://www.minnesotawildflowers.info/flower/wild-lettuce

You are so right.  That's it.  I was able to find the details and it seems to be from the Aster/lettuce family and is native to most of the US. 

Thanks you - all - for the help and direction if identifing this beautiful piece of nature.

http://plants.usda.gov/java/profile?symbol=LABI#

Stacie