We are up at our place in Williams, AZ (“Gateway to the Grand Canyon,” LOL). The remains of last years wildflowers all over the yard. We have a small poodle-ish dog, and he gets absolutely covered in burrs. The variety is pretty astounding. I found a new one this time, a seed head that looked like a tiny mace, with 1/2” long, very thin black spikes, each of which had a serrated edge. I was curious about how common a seed-dispersal method burrs were.