Yes, and yes. As someone from SE New Mexico, where the state tree is a tumbleweed, I can tell you that as a kid, I arrived home with cacti stuck to my shorts on more than one occasion. Accidentally, of course. Because there wasn’t a sign created*, extra capitals or not, that could keep this kid on a trail.
*Except for the Carlsbad Caverns signs, because I had a healthy fear of falling off into the black nothingness on the other side of the signage.