Apt plant names

On the ride down to Hualango, I had a too-close brush with a very unpleasant plant. Nicknamed "hormiga" (ant) by the locals, this plant has the most accurate name possible - wherever it touches you, your skin becomes blotchy and inflamed, and feels like there are a thousand tiny red ants crawling all over and biting you for the next ~8 hours. Fun name, but not so fun of an experience.