Juglans ailantifolia
Common name: 
Japanese Walnut
JU-glanz a-lan-ti-FO-lee-a
Juglans sieboldiana
Native to (or naturalized in) Oregon: 
  • Broadleaf, deciduous tree, to 40-65 ft (15-20 m) tall, broad, round crown.  Leaves alternate, pinnately compound, 60 cm long, odd number of leaflets, 11 to 17, each leaflet ovate-oblong to oblong, 7-18 cm long, serrate, upper surface bright green, pubescent at first but then glabrous or nearly, pubescent below, and densely granular and pubescent on the midrib and leaf stalk (rachis).  Male catkins 15-30 cm long; female catkins with 12-20 flowers.  Fruit globose to ovoid, sticky, rugose, thick shelled, 2.5-3.5 cm long; recovery of the intact kernel upon cracking is poor (see below).
  • Sun
  • Hardy to USDA Zone 5     Native to Japan; introduced in 1860
  • A sport of the Japanese walnut, Juglans ailantifolia var. cordiformis, is known as the Heartnut because of its heart-shaped nuts (cordiformis = heart-shaped).  Cultivars of Heartnut have been developed and are grown commercially.  The nuts of these selections easily crack at the suture and released the heart-shaped kernel in one or two pieces.
  • ailantifolia: ailanti, from Ailanthus, the Tree of Heaven, and folia, leaf.  Its large green leaves, with 11-17 leaflet, are reminiscent of those of the Tree of Heaven, Ailanthus altissima.
Click image to enlarge
  • plant habit

    plant habit

  • plant habit

    plant habit

  • leafy branches

    leafy branches

  • leaves


  • leaflets


  • leaflet, underside

    leaflet, underside

  • developing fruit (nuts)

    developing fruit (nuts)

  • young and old trunks, bark

    young and old trunks, bark