There are two very common galls that form on Canada Goldenrod, one that causes a globular swelling in the stem and another that causes an explosion of leaves at the top, clustered tightly in a leafy bunch that looks like a green chrysanthemum. It was that kind I found the remains of today, capped with a fluffy snow bonnet.
Luckily, I found enough intact heads to perform the exploding cattail trick again. In this video, it's my husband doing the pinching while I operate the camera. I had to make several videos, reducing the resolution each time until I obtained one that my blogger would accept.