Pterocarya fraxinifolia
Common name: 
Caucasian Wingnut
ter-o-KA-ri-a frak-si-ni-FO-li-a
Native to (or naturalized in) Oregon: 
  • Deciduous tree to about 80 ft (25 m), often multistemmed, with a wide crown.  Bark gray-black, deeply furrowed.  Leaves alternate, pinnately compound, 20-30 cm long, 10-25 leaflets, each 8-12 cm long, ovate to oblong-lanceolate, sharply-toothed, thin, green above, paler with midrib pubescence below.  Flowers, male and female in separate greenish catkins, male 12 cm long, female to 50 cm; bloom in early summer.  Fruit a nutlet, 2 cm wide with 2 semicircular wings; mature to brown in late summer, may persist into winter.
  • Sun, best in moist well-drained soil, adapts to medium loamy and heavy clay soils; tolerates drought.  Vigorous root system.  Suckers.  Needs a large space, best for parks.

  • Hardy to USDA Zone 6                 Native to the Caucasian region of Armenia, Azerbaijan, Georgia, Iran, Russia, the Ukraine and Turkey.

  • Pterocarya fraxinifolia is similar in appearance to Pterocarya stenoptera, Chinese Wingnut, however, the leaf rachis of P. stenoptera is winged and sparsely toothed whereas the rachis of P. fraxinifolia is cylindrical.

  • Pterocarya: from the Greek, pteron, "wing" and  karyon, "nut".        fraxinifolia: the pinnate compound leaves are reminiscent of those of Fraxinus, ash; folia, leaves.

Click image to enlarge
  • plant habit

    plant habit

  • foliage


  • leaves and flower cluster

    leaves and flower cluster

  • flower cluster and flowers

    flower cluster and flowers

  • trunks, bark, Knott St., Portland, OR (courtecy of S. Matthews)

    trunks, bark, Knott St., Portland, OR (courtecy of S. Matthews)