Teasel!
One year got a packet of seed, and started some down the bottom of the garden. They were glorious, beautiful flowers, seeds for the birds, seed heads for vases...
They self-seeded like crazy - the first two years, after that initial dozen plants, we were digging large numbers of them out of the lawn armed with gloves and knives.... the teasel 'down-side' is if they like the location, they seem to go on a growing rampage (who can blame them).
A relative spotted one two days ago, lurking at the back of the border, and before you could say 'Please! No!', it was culled. :( . That hardy young teasel had to have germinated from seed scattered via the initial batch of plants, some 10-12 years ago.
Lawns, prickly leaves, and bare feet are not a happy match!
But I still like 'em.