Something about blooming broomweed in October that seems to attract the bison. Over the years I've noticed they seem to like hanging around this weed during the heat of the day.
The Comanche boiled the flowers and leaves into a tea, then used the pulp for skin rashes and poultices. Some folks claim it is an insect and snake repellent. Have a feeling the insect repellent claim is probably why the buffalo like to lay around in it. Nature has a way of providing for it's own!
I did notice that the snakeweed had no effect on the ever present flies on the buffalo as this pic shows. Suspect the weed gives relief from mites and fleas though.
While trying to find out more about the medicinal qualities, found an unusual article in an Okla. wildcrafting site. During the 1918 pandemic flu outbreak (Spanish Flu) which killed thousands; a tea made from the boiled leaves and flowers was used extensively in the treatment of the afflicted. Makes me wonder what the buffalo would say about one of their favored plants!