I was told I have a lemon tree but it is producing green fruit that's 4 times the size of a lemon - in a pot about 5 ft tall.
Certified GKH Gardening Expert
Well, it might be a Ponderosa Lemon. It is not a true lemon but tastes like a lemon so many people call it so. It sounds like you received this from someone else, so it would have been an easy mistake for them to make.