The flowers have a dense, peduncle (have a flower stalk) and the terminal head, has involucral bracts (a structure surrounding or supporting, usually a head of flowers) is rigid and persistent.[4][6] The involucre is four-leaved,[7] It has a spherical head of flowers.[4] It has a cylindric calyx-tube, which is often slightly curved,[4] and is circumscissile (opens at the top) above the ovary.[6] It has 5 (rarely 4) lobes,[7] with the outer lobes slightly larger than the inner.