What did people do before the invention of toilet paper? That's a question that gets asked from time to time and there are a number of answers depending on what was available. The plant featured in this song is called mullein (Verbascum thapsus) and it has the nickname "Cowboy Toilet Paper" simply because cowboys sometimes used it as toilet paper. Its leaves are sometimes compared to flannel in texture and so it's easy to imagine that it might make a reasonable substitute for toilet paper in an emergency situation. The plant is not native to North America, but it got here in the 1700s and like the legendary tumble weed (aka, Russian Thistle or Salsola paulsenii) it spread like wildfire across the continent and became associated with the Wild West even though it was a newcomer. Even Native Americans quickly found uses for mullein and so although it's not a native plant it was soon incorporated into the lifestyles of many inhabitants of the Old West back in the days before toilet paper was widely available.