The Boyce Thompsoni hedgehog cactus, named after the great benefactor of the Boyce Thompson Arboretum in Superior, Ariz., allegedly grows “glorious magenta” flowers that emit an “irresistibly fragrant” aroma. It sprouts “showy red fruits” so tasty that early desert settlers raced to pick them before animals could eat them. Unfortunately, repeated visits to the arboretum have yet to provide first-hand confirmation […]