This grass appeared last summer in the road ditch along my friend's farm fields. We're trying to decide if it might be an ornamental grass that might look nice in a yard planting or if it might be an invasive species that she should eradicate post haste.
The fluffy seed head is quite attractive through the winter, and the closely segmented stems are rather unusual for Minnesota grasses.
Based on what I read about Equisetum on the Wikipedia page, it might be a good idea to make sure this thing doesn't spread beyond the ditch in which it is growing. I doubt the cattle in the adjoining pasture would like it, we don't want to eat it, and it sounds as though it can be invasive.
That is Pampas Grass: Cortaderia sp. (probably -jubata). It is invasive like crazy, and it grows huge, with razor sharp, long leaves. It is tender, tho, so I doubt it would survive the winter...(you live in MN?)
More postscripts...I can see how it could look like an Equisitum (spell?) because of the stalk segments. If this is indeed a Cortaderia, these stalks wave from the bush, which is a thick mound of grassblade leaves that fountain out from a core. The bush looks like "Cousin It" from the Addams family...like a green haystack.
They are really difficult to eradicate- unless the cold does away with it. Must have come off of somebody's decoration?
Here's Pampas grass at a similar level of detail, definitely not the same. Pampas grass (as in Cortaderia genus) is not going to grow in MN, although I think there's a species of Miscanthus that goes by that common name and is found there. http://k53.pbase.com/u36/jwalk/large/23717784.pampas2.jpg
OK- without actually seeing the plant, what can I say? I am familiar with Cortaderia & that whitish seed-head looks exactly like it. I am not acquainted with Phragmites at all. Logic would keep Pampas Grass out of MN, anyway.