OK, I Never Saw One of These Before…

Having rethought my eating habits as part of this weight management program I'm in, I've renewed my taste for walnuts. If weight is an issue, and especially if, like me, your overeating habits have to do with keeping your hands busy (I used to joke that I lost weight when I was dating someone because it gave me something to do with my hands while watching TV), walnuts are great, not just because they're low-carbohydrate, have the right kinds of fats and oils, and even some protein, but because getting them out of their shells is time consuming and requires complex hand movements. Rather than using an old-fashioned nutcracker and pulverizing the nut meat, I like to open a walnut by prying the shell with my pocketknife's screwdriver blade and remove the nut meat in just a few pieces.

I've also increased my patronage of local markets, in particular Dan's, who have a really well-done advertisement shown at the Alameda Theater (almost good enough to forget that you're watching an advertisement in a movie theater…). I like their walnuts, they're unbleached, typically nice and large, and as good a price as I see around.

Now look at the picture. Every other walnut I've ever seen has been, as they say in biology, bilaterally symmetric, i.e., in halves. You can even buy walnut "halves and pieces" at the store. Never seen "thirds and pieces". Until this week.

The walnut at the bottom appears to have a three-part structure. Now, while all vertebrates have bilateral symmetry, other morphologies (impressed?) are common in invertebrates, e.g., starfish, and particularly in plants. For example, cut an apple crosswise and you'll always find five seed pods in a pentagonal pattern.

So trilateral symmetry in a plant is by itself no big deal. But when every other individual of that species that you've ever seen is bilaterally symmetric, and you find one that's trilaterally symmetric, you take notice.

I still haven't opened it. I wonder what's the shape of the nutmeat? Some threefold analog of that sort of doubly-folded shape you can see on those rare occasions that you shell a walnut without breaking the meat, maybe? Anyone have an MRI scanner they're not using?

I'm serious about this. If there's anyone out there that knows something about this phenomenon, how frequent it is, the genetics (or epigenetics) of it, please comment.