From Tony Avent's fine article on growing ladyslippers ( ...Read Moretarget="_dgnew"rel="nofollow">http://www.plantdelights.com/Article/Cypripedium-Lady-Slippe... ) :
"This 1991 Werner Frosch hybrid is a cross between Cypripedium parviflorum var. parviflorum and Cypripedium macranthos var. speciosum. The result is a vigorous hybrid which, in mid-spring, produces 14" tall stalks of flowers with white pockets, occasionally stained with burgundy near the top, then complimented by twisted sepals of dark burgundy. (Hardiness Zone 5-7, at least)"
From Tony Avent's fine article on growing ladyslippers ( ...Read More