Weird Names: A 'Caucasian Wingnut' Is A Tree

The "Caucasian Wingnut" isn't the guy leaning on the railing.
It's the tree!

When I saw the title of this article,

Gnarled but glorious: In the shade of Vancouver's Caucasian Wingnut,

You can imagine my confusion! I thought it was about a palefaced redneck weirdo or something...