If you need a little help to understand the haiku, please read the following excerpt
from an article of the University of Texas History Corner.
« While a few players strapped nose guards over their faces, most went without any protection. Instead, they grew their hair longer, and at game time wrapped bandages around their heads and over the tops of ears (to prevent ears from being pulled and torn), which pushed the hair up into a mop. The mat of hair was supposed to be sufficient cushioning to prevent severe injuries.»
And… The name of this mat of hair : chrysanthemum-haired.