It reminds me of a couple of ground orchids I have seen, although they weren't as tall as your pictures show. Maybe they grow as tall in the ground - the ones I saw were in pots.

I Googled a picture of the ground orchid and you were on the right track I think, but the stem looks different. I would say that the plant most closely resembles a cross between the foliage of an iris and the stalk of bamboo. It did have small bluish black berries on it that fell off during transport if that helps at all. Thanks for taking a shot!

Its Belamcamda Chinensis (or the blackberry lily). Looks like the lower leaves were taken off to expose the stalk. The momma plant will die after blooming, but new ones come up from underground and the seeds germinate readily too so you will soon have a nice clump of it.

Another possibility is Iris confusa

http://helenie.blogspot.com/2008/03/iris-confusa.html