Figuring out Juglandaceae: the Black Walnut

Black Walnuts with and without husks
Golf Balls! And round brains!

Black walnut, along with the various hickories and the pecan, is a native Piedmont trees of the family Juglandaceae. They are large trees with especially leafy leaves (bipinnate leaves if you wanna be all sciency sounding), and have nuts of varying tastiness. The nuts have a fleshy coating covering, a hard shell, in some cases VERY hard, and the nutmeat looks like a pair of facing brains. The are good examples of a hardwood; the wood for these trees is most universally hard.

Juglandacea are very common native Piedmont trees; whole ecosystems are named after them. So they’re useful to be able to identify. Let’s start with the black walnuts, Juglans nigra. The rest of the local relatives are in genus Carya.

So, black walnuts, one of the tasty ones.

You can identify black walnuts by looking at the nuts and looking at the leaves.  Hickories and pecans have dehiscent nuts, meaning there is a crack somewhere along the husk. So the nuts have ridges. Walnuts (and pecans) do not. They have smooth husks, slightly bigger than golf balls or apricots. They also have the leafiest of the leaves, up to 23 leaflets per leaf. The other ones seem to be more in the 11-15 leaflet range.

Two other bits of black walnut trivia: First, the husks stain. They produce an excellent dye, and you can reasonably stain furniture by just rubbing it with a black walnut. Second, they are allelopathic, meaning that the plant produces a chemical (juglone) which discourages other plants to grow. Juglone is present in the leaves, any fallen bark, and the nuts. So they are often bare of cover for a decent way around the tree.

So, even if you want to make furniture, do not plant a black walnut near your veggie garden.

Dried black walnut leaf
Such a very dried leaf. But note that there is a leaflet at the end.

So, black walnut = stainy golfballs and lotsa leaflets.

And yes, this is a stupid time of year to be doing this, what with the leaves not leafing out yet,  But the damn things are everywhere, and it is tiring to not know which tree is which. So writing a guide will help solidify the differences.

Next week, pecans!

And one more final note, getting ANY program to stop autocorrecting “juglans” and “juglandacea” to “jugular” is really annoying. Apologies if any were missed.