Mallos
From Tolkien Gateway
Mallos was a flower that grew in the vales of Lebennin in Gondor, described as having the shape and colour of a golden bell.
Etymology
Mallos has a troublesome etymology. Though the first element is obviously malt, "gold", the second element can either be loss ("white") or loth ("flower"). The Westron name of the flower is given as Goldenbell.