This is a seedling of H. 'Chartreuse Wedge' that was registered by Dr. Jim Wilkins of Michigan in 2000. Growing into a large size (26 inches high) plant, it has shiny, heavily corrugated foliage with thick substance. Very pale lavender flowers appear in July.

According to The Hostapedia by Mark Zilis (2009), "Like all cultivars developed by Jim Wilkins,' isle Royal' is the result of careful breeding and selection."

Isle Royal is a National Park located in Lake Superior off Michigan's Upper Peninsula. It is noted for research on the predator/prey relationship between wolves and moose populations. Wow...how did I remember that?