Weird Sign

Agapanthus

I saw this weird sign today that I am hoping someone can explain to me. I know it is a joke, but I am fairly sure I am not fully grasping the joke. I know Agapanthus is derived from Greek to mean love flower, and I know it is a genus of flowers that includes what is commonly called the lily of the Nile. Thus clearly, Agapanthus is not going to be attacking anyone. I still feel like I am not fully getting this joke. Can anyone elaborate on it?

Edited to add: This has been proposed as a possible explanation. If anyone can confirm or knows something different, I would love to hear it.