It looks like an Elephants trunk :o)

Hehe i thought that 2 Amy

Great shot! Is it a Eucalyptus trunk?

Palmate
Yes it is .Well spotted ..

Palmate:

Well, I would know...as we grow more Eucalyptus species in California than anywhere in world, outside of Australia. Many species have naturalized here since the 1850's.

I think this is the reason why so many Aussies love California, because it reminds them of their home.