Flowers beginning with C

Thanks veggie   any information about the things I list on here is very welcome    . 90% of it will be things I’ve never grown before. How big does Cedronella get? I don’t think I found that information yesterday. Then I spent so long googling different plant names to find out when to sow them. I don’t have a clue which is which. All I know is the pictures looked pretty and I’d give them a go     . The other thing, if any of the plant’s I list are not perennial, please tell me. That also got quite confusing during my googling session   .