Question by Ghost from Scene 24: I have 2 trees nearly identical to Juglans nigra (Black Walnut), what are they?
I have 4 huge Black Walnut trees on my property in Northeast Missouri, and 2 other equally huge trees I thought were male Black Walnuts until I learned they are a monoecious species. The two trees in question have compound leaves very similar to the Black Walnuts except with smooth margins on the leaflets instead of the fine toothed edges seen in the others. The twigs are also much thicker, lighter colored, and slightly more angular; the bark is slightly smoother; and the flowers grow upright from the twigs on stalks. The wood seen when removing broken limbs is very similar to typical Black Walnut. If a seed, nut, or fruit is produced, it would be very inconspicuous as I have never noticed them in over 10 years of yardwork at that residence. The 4 trees that produce nuts every year are in the same location and conditions as the two trees in question. If this is not another species, why are there the differences I listed in them?
Best answer:
Answer by candy2mercy
They may be Persian or English walnut, Juglans regia, whose leaflets are smooth-edged. Walnuts also hybridize with each other, and sometimes native walnuts are used as rootstock for cultivated ones (at least that’s the case here in California). Maybe if those other trees are pure regia, they haven’t produced fruit because they aren’t well-adapted to the local area (which is why other trees are used for grafting).
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