Thanks everyone, E. tenellus works for me. I'll be interested to hear more about this change from tenellus...has it already been renamed? Does pygmy chain sword look any different? I'm assuming it grows lower to the ground...
So how narrow are those leaves, actually?
Well, it seems that you guys over that side of the pond have this plant down as E. tenellus whereas we, on this side of it, 95% of the time have E. tenellus that has 1 mm wide, needle-like, max. 2-4'' high leaves that turn reddish. It could be that your one might be E. parvulus -a native to the North America. It's said that one doesn't turn red (by e.g. Kasselmann).
The name change will be quite extensive. A new revision is on the way. I'll tell the new genus name for tenellus as soon as my friend's article is accepted for publication (has come back from the referees now). Hmmm... maybe I said too much even now, telling about the name change... Oh well, what I wouldn't do for you guys.