While watching Good Eats, ol’ AB mentioned that pecans aren’t actually nuts, but are “drupes,” as are walnuts and probably other things we call nuts. And of course, we all know that a peanut isn’t a nut, it’s a legume. So of the things we commonly call nuts, which ones are actually botanically/taxonomically considered “nuts?”
Hazelnuts and chestnuts. Filberts. Depending on who you talk to, walnuts and pecans (which is why, to split the difference, they get called drupaceous nuts).
Aren’t hazelnuts and filberts the same nut? They taste the same and their bushes are indistinguishable to my untutored eye.
They’re a different species (Corylus maxima) - ordinary hazelnuts are Corylus avellana (European Hazel), or Corylus americana (American hazel). They are very similar.
Of course (to further the hijack) Pecans are simply the American version of Walnuts and can be used fairly well interchangably in a pinch.
Donuts…
Um, no.
Wikipedia: pecan It’s a type of hickory tree.
Wikipedia: walnut They are from the same family, but are decidedly distinct genera. Much different flavors, too.
I think the technical term is actually “testes”.
OK, so what about nut allergies?
It hadn’t occurred to me before, but the old packaging howler “PEANUTS (Warning: may contain nuts)” makes more sense when you consider that peanuts are not nuts. And yet people with nut allergies are also allergic to peanuts, no? Why?
There are various walnut species including at least a couple native to North America: Black walnut (juglans nigra) and Butternut (juglans cinerea).
Not always. I have one nephew who is allergic to both peanuts and tree nuts, and another who is allergic to peanuts and soy protein, but not tree nuts.
(I am shamed.)
(But not nuts.)
Sometimes you feel like a nut
Sometimes you don’t
(No, i don’t think advertising has a cumulative effect. Why do you ask?)
I don’t think it’s particularly wrong to think of pecans and walnuts as the same kind of thing - as long as it’s not in a botanical context or anything. They’re not exactly the same, but they’re undeniably somewhat similar.
Ah, the much loved “Dese Nuts”
Well, only true if you consider a cow the same as an impala, for example. 
Yeah, you say that. But you’ll eat anything.
What do you call nuts on the wall?
Wallnuts.
What do you call nuts on your chest?
Chestnuts
What do you call nuts on your chin?
A dick in your mouth.
I crack me up.
I have a coworker who is allergic to tree nuts, but not peanuts, which (I guess) is somewhat unusual.
What, botanically speaking, are pine nuts? I once had a friend allergic to those.
I felt I needed to be helpful after posting a joke in a GQ thread.