I found this on the recessed top of the intake manifold of my car engine. It may have been there for weeks. It was likely brought there by a rat or squirrel who was unable to chew through the outer shell/husk. The white part seems to be where an animal gnawed on the outer portion. Note the orange color where it was apparently not chewed on. It likely was deposited in my engine compartment by a critter somewhere in inland/coastal southern or central California. enter image description here The air temperature when I found it (while changing a headlamp) was 106 degrees F (41 degrees C) and the temperature of the engine routinely gets well above that. It has been well-toasted.

The size-reference coin is a US one cent piece that is about 19 mm in diameter.

I think it had the very faintest citrus aroma when I first found it and I thought it was a small orange (orange outer skin, white pith) that had been dehydrated and then chewed on by a small animal. Then I shook it and it rattled - clearly not an orange. When I cracked it open with a large pair of pliers I found the 'nut' that you see in the images. It smells faintly nutlike and has a slightly waxy/oily finish - something like the appearance of a skinned hazelnut. Note that the 'nut-meat' has shrunk away from a dark, shiny skin.

I haven't cut or tasted the nut-meat myself on the off chance it is toxic.

Are there any forensic botanists out there?


1 Answer 1


I'm going to go with California Beaked Hazelnut (Corylus cornuta).

While it is hard to tell from the chewed outer, it has the reddish-brown colour of hazelnut shell, and inside the shell is a dark brown papery layer. The nut (without the papery layer) is smooth and rounded

  • $\begingroup$ Certainly looks very similar to hazel nuts I grew in IL $\endgroup$ Jul 22, 2021 at 17:13
  • $\begingroup$ This one is somewhat larger than any hazelnut I have ever seen. And I don't think I've ever traveled in that particular car as far north as any of the areas noted as its natural growing area. But that doesn't mean that it wasn't transported to somewhere I had travelled and was picked up by a naïve squirrel who couldn't figure out how to open it. $\endgroup$
    – OCPatch
    Jul 22, 2021 at 22:47
  • $\begingroup$ @OCPatch - people grow them in their gardens too; they are certainly available from nurseries. The nuts get up to about 4 cm/1.5 in long, so that's pretty big for a hazel, but not outside the realms of size for your one. The main argument against is the bumpy shell to my mind - hazels are all smooth AFAIK. Could be a pit from a (large) fruit? $\endgroup$
    – bob1
    Jul 23, 2021 at 0:52
  • $\begingroup$ @bob1 - Good point about people maybe having them as a novelty plant. If it weren't for the orange and white husk I would have guessed it could have been a small avocado pit. It could have been a small whole avocado but for the red/brown/orange outer skin and the hard, dried husk on the outside. $\endgroup$
    – OCPatch
    Jul 24, 2021 at 17:08

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