Yes Molly, it is a perennial, hardy to zone 5. See the link below for more information.

Here is a link that might be useful: Missouri Botanical Garden

willameadows, thanks, hopefully, mine will live.

it is also .. IMHO .. and the linked website .. a highly invasive plant .. they note.. and i quote:

Spreads by runners and can be very invasive.

there is nothing worse than getting enthralled by a plant.. and then a few years later cursing its existance.. and not being able to kill it all ... been there.. done that ...

good luck
ken

Thanks Ken, will keep it in check.