Arthur Temple College of Forestry and Agriculture

Cyclocarya paliurus - Wheel Wingnut
A member of the Juglandaceae, this species is way off the beaten path and I’ve rarely encountered the species in the USA except in a few botanical and private gardens. However, I have seen it in eastern China and it never fails to charm whenever it’s in seed in the Fall. The SFA Mast Arboretum is home to one tree that has been producing nuts for several years and that tree provided the image. It’s been pest free and shares its cousin Pteryocarya’s penchant for bearing a heavy wingnut crop. In the case of Pterocarya – and we have enjoyed several species over the years – we have found seedlings here and there and have questions about the invasiveness of that species in our region. We have already removed one monster Pteryocarya out of fear of that. On the wheel wingnut, the female catkins are the key feature and can reach over twelve inches long, bearing small winged nuts surrounded by a membraneous wheel-like wing around the tiny nut. They are quite charming and one can imagine them spinning away in a Fall storm hoping to find a new home. Dark green pinnate leaves have been large, dark green and clean. Cyclocarya is a genus with a single species, and while once treated as a Pterocarya, it has been partitioned away. Pterocarya has two wings at the sides of each nut. I understand that the seed is somewhat difficult to germinate, perhaps complex – Dr. Jeff Adkins, SFA Horticulture, is running a large seed crop through some germination trials at this writing (November 2009).

Dr. Dave Creech, Director of SFA Gardens