I'm sure different parts of the world have different weeds.   For me, the worst are: Variegated - someone planted it there, then it decided to take over the earth.   Nonvariegated - probably reverted from variegated, and even more aggressive.   Bishopweed, also called Goutweed (Aegopodium podagraria); It's sold as an ornamental.  It has brittle underground stems, so when you pull it up, it leaves…