'Dietrich' (kentuckiense x calceolus) is a large and especially robust hybrid which can grow to two feet tall. The flower colouration resembles the European lady´s slipper (C. calceolus) and the North American yellow lady's slipper (C. parviflorum) but its flowers are some of the largest of the Cypripedium hybrids. The lip, however, varies between yellow and cream. Long-lived flowers in mid to late spring. Grown from seed. Plants will resemble the image but may not be identical. Lady's slipper hybrids are much more vigorous and easy to grow than species. Blooming size.