Pterocarya fraxinifolia: Caucasian Wingnut
- Photos to aid in identifying this tree by its leaves, bark, and other characteristics.
- http://www.bomengids.nl/uk/soorten/Gewone_vleugelnoot__Pterocarya_fraxinifolia__Caucasian_wingnut.html

Pterocarya fraxinifolia
- Images of the whole tree and its buds, flowers, and seeds.
- http://www.arborea.se/ptefra.htm

Pterocarya stenoptera
- Photos and description of the Chinese wingnut tree.
- http://www.greenbeam.com/features/plant011998.html

Pterocarya stenoptera: Chinese Wingnut
- Fact sheet about this tree, including a photo.
- http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/trees-new/pterocarya_stenoptera.html