Okay, so you know how sometimes when you have a mosquito bite, your skin gets all puffy and bumpy? Well, something similar happens to a special kind of plant called a rose.
See, sometimes a tiny insect called a wasp lays an egg on a rose's stem. When the egg hatches, a little baby wasp starts growing inside the rose stem. But here's the cool part: as the baby wasp grows, the rose's stem gets all swollen and bumpy. It's like a big, puffy bump on the plant.
People call this swollen bump a "rose bedeguar gall." It's a little like a rose version of a mosquito bite! And even though it might look a little funny, it's actually sort of protective for the rose. The wasp baby lives inside the really tough, bumpy part of the rose stem, so it's harder for other animals to get to it and eat it.
So, that's what a rose bedeguar gall is - a bumpy, swollen part of a rose stem that's caused by a baby wasp growing inside. Pretty cool, huh?