There are some pubescence differences which will help to distinguish Butternut from the Black Walnut, even when the distinctive dark pith is not exposed. In J. cinerea, there is often a pad of dense small hairs extending transversely along the upper margin of the old leaf scars; in J. nigra, this pad is absent, although the circular area of bud pubescence is confusing, and some specimens are ambiguous. The underside of the leaflets in J. cinerea is +/- densely covered with mostly stellate hairs, while in J. nigra the pubescence is sparser and mostly of simple hairs. The pubescence of cinerea, including that on the fruit, is more clammy than that of J. nigra. Persons familiar with the species in the field will also know differences in fragrance of the foliage and fruit and in stain from the husks--all difficult to expresss in words (Voss, 1980).
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