Seeds Bowkeria verticillata Natal Shellflower Bush. This wonderfully fragrant 4-6 foot shrub is hardy in zones 8a-11. Have slightly hairy, bright green leaves. In late winter to early spring unusual flowers come into bloom. Large pendant white flowers that resemble sea shells have a sweet lemon scent. These dustlike seeds need only be sprinkled on the surface of good potting soil and kept damp.