Thanks Michael, Chrissie and Tina.
I'm overwhelmed! Its great to see such a quick response to this posting, and to get so much good advice, and thanks for that useful link Tina.
With the exception of 1 neutral, it has all positive ratings on your Daves Garden site Tina, and seems to be a favourite with a number of the contributors. Do you grow it?
It seems to withstand the frost and snow of your hard winters, and your blistering summer temperatures.
Your "full sun" is a LOT more severe than ours in the UK.
Ive passed the info on to the owner of the plant, and Ive been promised a wee pick off the roots - which appear to be little bulbs.
Do you grow yours outdoors Michael?
Do you find it invasive Chrissie? Any photos on your website?