What do you call a plant that's always sad?

This joke really digs into the wonderful world of wordplay, specifically a pun. The humor blossoms from the double meaning of the word "weeping." On one hand, "weeping" refers to crying or being sad, which is the setup's hint. On the other, it's the actual name of a type of tree known for its distinctive, drooping branches that hang down as if in perpetual sorrow.

Weeping willow trees (Salix babylonica) are famous for their elegant, flowing branches that cascade towards the ground, giving them a somewhat melancholic appearance. This natural characteristic is what inspired their name centuries ago and makes them the perfect subject for this plant-themed jest. They've even been associated with sadness and mourning in literature and art throughout history, which only strengthens the comedic connection in this groan-worthy, yet charming, piece of gardening humor.