Horsetail: One Person's Weed is Another Person's Scouring Pad

Writing for the blog often makes me question things I think I know.  I took these pictures of horse tail at the Helen Louise McDowell Sanctuary, but is that really what it is?  Or just the name we tend to use?  It does seem to be horse tail. 


 
My first stop on the google express got to this at gardenstew:

"I have a weed growing in a bed in my yard (Horsetail). From my research I have found out that this is a very hard thing to get rid of. Unfortunately it has begun to spread in my lawn and into another vegetable bed that I have. I don't want it to get much further, but from what I am reading most weed killers do nothing for this. Has anyone ever dealt with this weed before? Any suggestions? (I have pets and don't want to expose them to anything toxic in my yard.)

Thanks"

 (You can find suggestions for getting rid of horsetail there at gardenstew and also at the UBC botanical garden site.)

But horsetail has beneficial properties too. 

Alaska Herbal Teas tells us:

"Horsetail is edible, but not choice. It must be boiled, as it is toxic raw. Some Athabascans use it as a seasoning. A fluidextract of the sterile stems and ashes from the burnt plant are used for medicine against kidney and bladder trouble, stones, ulcers or wounds in the bowel, and externally on sores. Horsetail has historical uses for cleaning and polishing. Its high silica content makes it good for scouring and soap preparation."

There's overlapping info at  Wikipedia:

The Water Horsetail has historically been used by both Europeans and Native Americans for scouring, sanding, and filing because of the high silica content in the stems. Early spring shoots were eaten. Medically it was used by the ancient Greeks and Romans to stop bleeding and treat kidney ailments, ulcers, and tuberculosis, and by the ancient Chinese to treat superficial visual obstructions. Rootstocks and stems are sometimes eaten by waterfowl. Horsetails absorb heavy metals from the soil, and are often used in bioassays for metals.

According to Carolus Linnaeus, reindeer, which refuse ordinary hay, will eat this horsetail, which is juicy, and that it is cut as fodder in the north of Sweden for cows, with a view to increasing their milk yield, but that horses will not touch it.