By Olivia7
United States 
I have a tall plant about 4' with cos lettuce-like leaves with spines on the back rib of the leaves and on the stem. The whole plant is a very bright green. A neighbour says it is a teasel but I cannot find any photos on line that don't only show a dried teasel and there are no signs of one appearing yet and the leaves seem too big for the odd one seen on the photos. Thank you
10 Jul, 2012
Answers
Brilliant, thanks very much, it does look like this but without any suggestion of a teasel head as yet (I am in Devon in the UK altho above the flag suggests I am American - I know not why!). On return from 10 days away I found several of them about 3 - 4' high and, not knowing what they were I tried to kill them with Roundup on the growing points as suggested on their packaging but it doesn't seem to have done much except turn those leaves a bit yellow. I hope I haven't ruined them as I need a few more dried teasel heads to add to an arrangement I have had for a few years. I have to say, when you see them dried on the side of the road they bear no relation to what I am growing at the moment!
10 Jul, 2012
When mine flower they look pretty but the real bonus is the goldfinches who really love the seeds
10 Jul, 2012
When do they flower? Shall wait with bated breath for the goldfinches.
10 Jul, 2012
I've got two that I asked about a while back, having been told they were borage! They are now enormous- nearly six foot high with lots of flowers coming. I'm going to leave them for the goldfiches but I don't want to grow them again as they take up an awful lot of room.
10 Jul, 2012
It does sound like a Teasel. Dipsacus fullonum
This is an image of the plant which may help.
http://caliban.mpiz-koeln.mpg.de/thome/band4/tafel_102.html
10 Jul, 2012