Tulip

We are told that in Persia the tulip, whose blossom in its native country is
scarlet, while the centre of its glowing cup is black, is used to express warm
affection; and, when sent by a lover, will convey to the object of his
attachment the idea that like this flower, his face is warm and his heart is
consumed as a coal.~ Anne Pratt, The Field, the Garden and the Woodland, 1838

According to Persian legend, the first tulips sprang up from the drops of blood shed by a lover and for a long time the tulip was the symbol of avowed love.