Lincolnshire couple Ann and Bob Armstrong have established the collection after growing the plants since the 1990’s.
When a former National Collection Holder retired, the couple saved many of his seeds and started their own collection.
Other seeds have been sourced from botanic gardens and specialist nurseries. Adding to the collection is not easy as over half of the 60+ members of the genus are not in cultivation in the UK.
The Armstrongs are keen to source the species C. bhutanica, dicentrifolia, thalictrifolia, canescens, nervosa, meleagris, bulleyana and foetens.
The collection now consists of 27 species, and the couple have a further six plants they are waiting to flower before they can identify them properly. They are establishing a web-based picture gallery.
Codonopsis is a genus of flowering plant within the Campanulaceae family and originates from Asia, Pakistan, Japan and Korea.
Plant Heritage conservation officer Mercy Morris said: "Codonopsis are a fascinating and beautiful genus, and I would encourage anyone who is able to help source plants for Bob and Ann to do so. The more research they are able to do as collection holders, the more future horticulturists will benefit."
The Armstrong’s will be opening the Collection to the public on 15 June from 11am – 5pm. See:http://www.nccpg.com/Events/Codonopsis-Open-Day-(3).aspx