Thanks to *everybody* who answered me! We called it snake grass when we
were kids, but I didn't realize it was the real name. I found no
commercial vendors who carried it, but several folks on eBay were
offering plants, so I put in a bid. I'm planning to put it in a new
raised bed, so I'm not as worried about its invasiveness, since I can
control spread so much easier in raised bed.

It will be lovely to have a little reminder of my happy childhood
summers here in the garden of my middle age. Thanks again to all who
helped with information.

Priscilla