Plant's Sticker is a term used to describe a type of plant that has a thorny stem. The crossword solution for this term is THORN, which is a five letter word. A THORN is a sharp, pointed structure that grows on certain plants and trees. It is often used as a defense mechanism against predators. Thorns can also be used to attach the plant to other objects, such as fences or walls. This is why Plant's Sticker is an appropriate term for this type of plant.