Iris lactea is so common across China it is just called Iris. It occurs in many different environments and may well be more than one species. Because it produces seed readily and can tolerate a wide variety of conditions it is a natural to consider as a parent involving more difficult growers.

"Many years ago Denver Botanic Garden had at least three very different I. lacteas growing in their garden. Each had a somewhat different bloom time and stature. The earliest to bloom was one tentaively identified as 'Hyacinthiana'. It formed a low mound of foliage like other alpine plants and the flowers formed a mass of bloom above the foliage. Sometimes alpine plants lose their tight form when brought to lower elevations. It is possible that 'Redundant' is this same plant but growing at lower elevations a taller plant but stil very nice. It also seems possible that those three variations represented entirely different unnamed species."--Bob Pries

Several variations of Lactea have been used in hybridizing; One noteworthy variety is Iris lactea var. grandiflora which is easily twice the size of regular lactea. See herbarium specimen below comparing the two.