From Tony Avent's fine article on growing ladyslippers ( ...Read Moretarget="_dgnew"rel="nofollow">http://www.plantdelights.com/Article/Cypripedium-Lady-Slippe... ) :
"This 1998 Werner Frosch hybrid, named for cypripedium grower Sebastian Urban, combines the genes of the east coast Cypripedium parviflorum var. parviflorum with the northwest US native Cypripedium montanum. This long distance romance resulted in vigorous 23" tall plants that produce narrow flowering stems topped with white pocketbook-shaped flowers, backed by prominent twisted red-burgundy sepals. The Cypripedium montanum parent passed along both a slight fragrance and the multiple flowers per stalk trait. (Hardiness Zone 4-7a, at least)"
From Tony Avent's fine article on growing ladyslippers ( ...Read More