Cactus Family Tree

Okay, so like, imagine someone's family tree is a cactus. A cactus is a plant that's, like, super prickly and annoying, right? And someone says everyone in that dude's family is a prick. So it's saying they're all annoying and unpleasant, just like a cactus. It's funny 'cause it's rude and unexpected! And you are not smart either.