The new plant was selected ahead of the Princess’ arrival for its buttermilk yellow flowers.
Drointon owner Annabel Graham said: "We have been keeping our cultivar closely under wraps since the Duchess of Cambridge announced her pregnancy last September. We are delighted to mark this momentous occasion with our new Auricula and are sure it will be popular because of both its namesake and beautiful, soft, dusky, buttermilk flowers."
The plant’s colouring matches the dress worn by The Duchess of Cambridge on the steps of the Lindo Wing, from the British designer Jenny Packham.
Three Counties Agricultural Societ chief executive Ken Nottage said: "We’re so pleased that Drointon Nurseries have chosen RHS Malvern to unveil their beautiful new Auricula ‘Princess Charlotte’. We’re thrilled to be marking the arrival of not only a new royal, but also celebrating this and all of the other new varieties that are launching here in our 30th anniversary year. The floral marquee is always a crowd pleaser and Drointon Nurseries have become stalwarts of the show, winning best in show in 2014, just one of a hat trick of RHS gold medals."