Wednesday, September 19, 2012

Heartnut, a cultivated Japanese Walnut


Heartnut hull, shell, and nut


Heartnut shells chewed open by squirrels
Today I picked Heartnuts (Juglans ailantifolia var. cordiformis) for the first time from a street tree near my house. I noticed the tree a couple months ago and was having trouble identifying it until I noticed some old heart-shaped nut shells beneath the tree.





A cluster of 10 Heartnuts
Leaflets with short petiolules and asymmetric basal lobes
Heartnut Bark is light grey and coarsely fissured
Heartnuts are a cultivated variety of Japanese Walnuts (Juglans ailantifolia) that grows about 60 feet tall and 16 to 36 inches in diameter with coarse, light grey bark. The leaves are very large reaching 3 feet in length and densely hairy with 11 to 17 pinnately arranged leaflets. Leaflets are ovate and 1.5-3 inches wide and 3-8 inches long; they have pointed tips, asymmetrically lobed bases, very short petiolules (less than 3/16 of an inch), and sparsely pubescent upper sides and densely haired undersides. Sometimes the terminal leaflet is missing or fused to one of the the first lateral leaflets giving it an odd appearance. The nut husks are fuzzy, egg shaped, 1-1.5 inches long and not quite as broad. Nuts are often in hanging clusters of up to 10. The husks can easily be removed by gently stepping on them and rolling them slightly beneath your shoe. The nuts are slightly smaller than the husks with a distinctive heart shape and a smooth outer shell and a significantly flattened appearance when viewed from the side. They crack easily to reveal a wing-shaped nut that is easy to remove unbroken. Like most nuts, they will be best after they are dried for a few months. Hopefully I will find a few more trees because the squirrels got most of the nuts from this one. I removed the husks from the few dozen nuts that I collected and will store them in a dry place until Christmas. They are supposed to have a sweet taste that lacks the strong aftertaste of Black Walnuts (Juglans nigra).
An odd Heartnut terminal leaflet doing double duty as a lateral leaflet.








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1 comment:

  1. I just read on Japanese Wikipedia that they use the hard and sharp shells of this tree for studless tyres

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