the yellow flowers to stop

I’m in the back of a bus to Berlin, I told him, wondering how they get the yellow flowers to just stop all of a sudden.
What? he said, and I sent him a picture on the telephone of what I was looking at, Danish meadows dense with something that made them yellow, totally, until with a disorganized border that was obviously following its own orders the yellow thing stopped growing and a green thing began. Swirls of color. Waves washing on a shore.
I think that stuff is called “rapeseed”, he wrote back.
I said, Thank god.
He said, There must be a better name for it.
I said, How could there possibly be a better name for anything at all ever?
I said, Murderplant.
I said, Punching people in the facetree.