I ride my bike for middle distance trips--where it's too far to walk but I'm too cheap to buy a bus ticket. Sometimes the traffic is a little scary and I'll ride on the cobblestone sidewalks. The other day, while trying to avoid traffic, I brushed up against a tree that was hanging over the sidewalk. 

I survived.  

Here's the tree.   

Now take a look at one of the mega-thorns that are all over this thing--they're bigger than 16 penny nails!

I actually got stabbed while trying to take that photo to show the relative size of the thorns. They are *very* sharp.  I was lucky I didn't get impaled by a dozen of them while brushing by on my bike.

It could have been worse, I might have been biking in Arizona...