Originated by Mark Zilis of Illinois and Wm Zumbar of Ohio, this cultivar is a sport of H. 'Royal Standard'. This hosta grows into a large size (26 inches high) mound of wavy, shiny foliage of a medium green color with a wide, white marginal variegation. The leaves are slightly corrugated and are very shiny on the bottom. True to its heritage, it bears fragrant white flowers in abundant numbers from mid-August into September.

According to The Hostapedia by Mark Zilis (2009), "This is probably the same plant as 'Royal Rim'..."

A diadem is a jeweled crown or headband that is worn by a king or a queen as a sign of their authority.