Yes the flower is supposed to go there, there's just a specific combination of candles that need to be lit in order for it to be safe. Try reading the books in the bookshop for hints on which candles should be lit, and then one of the news articles on the outside of the Four Winds building will help you determine exactly which those should be.
You know, I am really disappointed in this part of the game. I read that nightshade book several times looking for clues to the candles. I even looked up those symbols on line and still didn't see why I should group those 6 signs together having no prior knowledge of those symbols. Now i have unwanted knowledge of another flower with the other elements to empower that I don't want.
I expect that when i got the hint I should feel, like I just didn't pay attention or give it enough time. But I can't say that about this. For me, this was an unsolvable puzzle without prior knowledge of the origins of those symbols. Nothing on that horoscope says anything about grouping them by elements, just saying something about a watery crab is not enough. I had to look up further that grouping them by elements was the key. I've played all the King's quest games and this is the first time I can say I couldn't solve a puzzle even after I've been given the answer, there was no way I would have gotten it. Not without prior knowledge of how those group together and where they come from.
There was no indication how many candles should be lit, so I spent all my time trying to group them by color, by the rays coming out of the stones, and other endless combinations.
In another thread you compared this "difficult puzzles" to other kings quest games like the cliffs of logic was one example you gave. I disagree, as I solved the cliffs of logic without aid, but there is no way I could have gotten the candle puzzle. Even after reading the nightShade book followed by the 4 winds horror-scope, there is no way.