These are also referred to as Intersectional Hybrids - They are crosses between herbaceous peonies (P. lactiflora), from which they inherit their hardiness, and tree peonies (P. suffruticosa), from which they inherit their unique colors, handsome foliage and long bloom time. The Itohs have clean dissected foliage which makes a handsome architectural statement thru the fall, long after the old-fashioned peonies have collapsed. They start blooming in early June with large showy flowers opening in succession thru the end of the month.