Pedicularis superba, which grows in meadows and around woodland edges in south-west China, will be launched by Edinburgh-based Kevock Garden Plants, three-times winner of the event's Best in Show award.
Pedicularis belongs to the lousewort genus and the plants have colourful, hooded flowers borne on tall stems above attractive dissected foliage.
They have a reputation for being ungrowable because they are semi-parasitic, but owners Stella and David Rankin have succeeded in bringing half a dozen species to flower.
Stella Rankin said:
"Some are from unidentified plants and others have names that should be regarded as probabilities rather than certainties. However, they are all beautiful, colourful plants with very pretty young foliage."