I don't know if this will be of use, but I found quite a bit of info on Heuchera villosa Magnum while looking for heucheras for my garden.
H Magnun is a hybrid of H villosa from Thierry and Sandrine Delabroye.
http://www.plantdelights.com/H...
Leaf size is 8 to 10 inches'
Average height and spread is 1 ft by 2 ft ( some sites have H villosa hybrids growing as tall as 18-20 inches with bloom scapes as much as 28 inches) IMHO, I think those dimensions are possible if the plant is grown in near perfect conditions
This link is to the e-mail address for Sandrine and Theirry Delabroye
http://www.mytho-fleurs.com/Sa...
