Walnuts - Juglans regia - are dicotyledons. They have two seed-leaves, and the nut reflects this in its shape, being bilaterally symmetrical. So I was surprised when eating my way through a bag of walnuts to find one that was trilaterally symmetrical.

Does this mean that this mutation would be a tricotyledon? It wasn't just shell features: the interior nutmeat followed the three-lobed plan.
So how common is this mutation?


  1. I just found a walnut just like this, three lobes just like yours. Found this picture when searching to see what type of mutation it might have been. So cool to be able to show my kids. :)