Has Anyone Ever Seen This?
At first I thought it was a tomato or nightshade... until I realized it was growing on the leaf of some creeping charlie! Now my understanding is creeping charlie is invasive, so has some native insect discovered that it likes creeping charlie, or has some non-native insect found it?
This is a gall (which is a harmless tissue swelling) caused by a type of tiny gall wasp that laid it's egg in the plant. Both the plant and the insect are non-native.
Here is a page that shows what you would find inside:
Ground ivy or Creeping Charlie is non-native, and an aggressive grower, but is not really considered an invasive plant.
Wow, Christine, that is fascinating, thank you!