I lived in England for a few years in the late 90's. Just this morning I came across an old plastic film can with Teasel seeds I had collected in 1998. I was pretty sure they were dust by now but was amazed to see most of them intact! Out of curiosity I took one of them and cut it in two and was astounded to see white inside. Just for the heck of it, I've taken half and sown them in soil. It will be interesting to see if any germinate.
Being essentially weeds, I'm thinking they have a pretty long shelf life. Stay tuned for results!
