Have a bed of Black Eyed Susans around an oak tree. Was cutting spent flowers off of them this morning and noticed what looked like a giant fuzzy caterpillar on top of one. I quickly realized that it wasn't a caterpillar but the flower head itself. It looks like 2 flowers grew together to form one gigantic flower head. The stem was unusual too in that it was rectangular- approximately one half inch wide by an eighth of an inch. The remainder of the flowers on the plant were normal. Has anyone seen this happen before? Does this occurrence have a name?
It's call fasciation.
It's not terribly rare, lots of photos and info available online. Once you know what it is, you'll see it other places and in other plants. Interesting! Thanks for sharing your photo.