'Dooley' (Dooley 69-E) is a rare hybrid of Persian walnut (Juglans regia) and black walnut (J. nigra), though some growers suspect it is a backcross toward Persian walnut rather than a first-generation cross. It produces medium-sized nuts and is very productive, and it has been used as a thin-shelled parent for hybrid seedlings. Grimo Nut Nursery rates it for zone 6a.