Hi Again -

Thanks for the suggestions. (Veratrum viride, Yelllow Lady's Slipper,
Hosta.)

It didn't seem to me to be any of those - so I
decided to write to Rodney Bartgis (of TNC) who knows the canal very well.
Anyway, his suggestion was Epipactis helleborine.
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242101586
It's said to be widely naturalized, but there's certainly nothing close to
where I found it where it grows. I guess a bird flew it in...

According to Cronquist - it flowers July-August - so I'll have to keep it
in mind and go back and see what it looks like then.

--Kathy