Hi Janice, I'm afraid I can't answer your question, but wanted to share some info on my potted dwarf Meyer lemon tree, when I bought the tree it was thornless...it took about the 4th year and I noticed it started getting a few thorns...none prior to that, so I'm not sure if it gets them after a certain age or it has something to do with the particular variety the graft was taken from? All I do is cut them off and I've never had any problems from doing that. I have also heard of some Meyer trees with no thorns, so I am not sure why some do and some don't...hopefully someone here that knows will share it with us. As long as it continues to bloom and give me fruits, I guess I have no option than just to remove them once in a while. Luckily, only a few branches have them on occasion, I've been known to prune the ones that have them as long as the branches don't have any blooms. Good luck with your tree!

Mine has thorns. I grew my plant from seeds and so I always thought meyer lemons had thorns.

MIne will puncture a jugular......beware when picking fruit from inside the canopy.

Mine is starting to get branches with thorns and I’m removing them. It’s a 16 year old grafted miniature Meyer and I always get lots of fruit

My understanding is thorns are more common on younger trees. Also, water sprouts tend to have bigger thorns. If those branches are water sprouts, many people recommend removing them as they tend to be more of a drain on resources than a benefit to the tree. Water sprouts typically grow vertically and/or grow very fast, frequently outpacing other parts of the tree.