Spike

I was trying out the macro setting today. Discovered you need to be quite brave to get close enough to tropical spiders to make it worthwhile, so we'll make do with this tree instead.

It's huge: diameter of at least a metre and at least as tall as a big horse chestnut. The trunk goes straight up for 40 feet before you get any side branches, and the whole thing is covered in these vicious spikes. Cool tree.