True Citronella is a grass, a tropical species. Perhaps if you could take pictures of this plant, we could ID it for you. It's very likely a lemon balm, which is purported to repel mosquitoes.

Dear Jo,

I would love to see the plant too, and to hear your description of its fragrance. As Rhizo said, both palma rosa and citronella are grasses, very similar to lemon grass in appearance and culture. They are each such lovely smells, but since the plants are not free with their fragrance (you have to pinch the shoots) are so large, are not hardy here, and are sharp leaved (like corn) I not focus on them. I would love a little loveable cintronella plant that was like lemon balm though! I love the rose like fragrance of citronella. If you have located a variety of lemon balm with a citronella odor, please tell us about it! Or could it possibly be a mint?

Best wishes,
Sincerely,
Matt