I suppose it's a bit of a cliché representing the cemetery with a wilted flower. In reality, the municipal workers spend the last few days of October cleaning and tidying the cemetery until it is immaculate. Then families come with pots of (mostly) chrysanthemums and festoon the graves with them (see extra).
Don't ever give chrysanthemums as a gift to a French person because they are exclusively associated with death. I love these blowsily extravagant flowers though, and wandering the cemetery at this time of year is always a treat -- click right from here for more. It does make the unvisited tombs look a bit more melancholy, but even these are at least tidied up. See also my blip from two years ago; Spanish cemeteries are festive places on this day.