Echinops bannaticus 'Star Frost' produces thistle-like, golf ball-sized spheres of white that float above the garden in summer.

Echinops ritro ssp. ruthenicus 'Platinum Blue' is a globe thistle with thistle-like leaves, silver stems and blue spheres of starry flowers.

Echinops ritro 'Veitch's Blue' is a great, somewhat old-fashioned perennial with wonderful shiny spheres that turn blue as the flowers open which ushers in a period of honey bee madness.

Echinops sphaerocephalus 'Arctic Glow' has spiny grey-green leaves and intriguing, spherical, white flower heads in summer.