Joe Harvey has had a plant registered with the ARS called 'The Porcupine' which is listed in the Spring ARS Journal. Here is a comment on it by Jamie Ellison from the Annapolis Valley in Nova Scotia: “A fantastic hybrid has arisen in NS (bred by Joe Harvey using R. makinoi with R. degronianum ) affectionately referred to as "The Porcupine". The plant is almost tropical looking maintaining the great makinoi foliage but on a very sturdy plant. When the new foliage breaks, the leaves stand straight up looking like a porcupine under attack. The new growth is long and rapid. The plant under cold stress looks even wilder when the long narrow leaves roll and droop. John Weagle can give more specifics. This looks more like a well grown R. makinoi slightly on steroids and nothing like yak or other yak types”.