So the OP should get ride of something that she has indicated has emotional value to her but only in that location, to please a boss that hasn't commented again? Sounds like boss has forgotten about it so why should OP act? Boss is unlikely to even notice the accommodation given to her.
I am totally open to if boss notices again, OP acting immediately. But why act when it is likely not the problem and unlikely to be noticed?
The boss likely felt that she'd made her request and it would be awkward or harping to bring it up again. I agree with the suggestion to take a picture. The plant may have sentimental value, but isn't worth awkwardness in your relationship with your boss. Keeping it around is one of those things that may seem minor to you, but may seem to the boss like something too minor for her to make a big deal out of, but still a statement about your priorities.
I agree with this. Boss made an effort to keep bananas out of the OP's
smell - I think the OP needs to do something similar with this plant. Take it home for awhile to prove that it isn't the plant - then when the smell still lingers, you can bring it back. Or do what PPs suggested and take a photo of it, and have that in the office instead.
I think you need to show boss the same courtesy she showed you. I understand the plant won't have the same meaning at home - that's unfortunate, but not worth creating an awkward situation with your boss.