Where does the Hydra among the plants come from?

When the heads of the mythological monster Hydra of Lerna were cut off, they kept coming back. This is also the case with Fallopia japonica, better known as Japanese knotweed. Undoubtedly, you have already seen it during one of your bike rides or walks. It is the most aggressive plant that we can now spot in our area. Pulling out rhizomes yourself does not lead to the destruction of this plant. But to whom do we owe this Hydra among the plants in our regions? The story leads us to Leiden. Here's an interesting "did you know-story" for your companions on your next hike or bike ride.