I think this lotus, and jan can correct me here if
I'm wrong, is one that came from a project pond set
up by Washington State University.
The fellow was testing lotus to see if they could become
a food crop in Washington for the Pacific Rim market.
He retired and his project was not continued. Folks were
able to come in and dig them up. A very nice fellow from
Yakima dug up some and brought some of them to jan
and me. (I killed mine, then I killed the divide jan gave
me last year.) So this is my third attempt at this particular
plant. (Also killed some I started from seed sent to me
from someone on the watergardening board... but that's
another story).

Anyway, these lotus, I expect, should be hardy to, at least
zone 7, but I think they are hardier than that if he was testing
them for overall Washington which probably ranges from zone
9 to.... oh, I'd say zone 5. My SIL, who is just over the boarder
in Idaho is in zone 4. She hasn't tried lotus yet but has ten
green fingers so I wouldn't be surprised if she does someday.

kathy