Do you mean that the flower buds have turned black?

Or are they right down where the leaves join the main stem?

If as Owdboggy says, they are on the stem at the leaf axils, these are simply bulbils which many lilies produce. If you carefully remove them when they are larger, and plant them in small pots, they will produce more lily plants of the same variety.
You will have to wait for a couple of years for the new plants to reach flowering size, but in beautiful warm Cornwall they might grow faster than that!