Response from Margaret Thorne.
Meconopsis gakyidiana is a validly published name, so you should definitely be using it for your seedlings. The two species are closely related, so it is to be expected that the seedlings will be very similar. The differences only start to be evident once the plants grow larger and if you are growing both species, it will be extremely interesting for you to compare the two species and share your photographs on this forum.
The paper describing Meconopsis gakyidiana and its diagnostic features can be found at this link:
https://journals.rbge.org.uk/index.php/rbgesib/article/view/193 Although it is closely related to Meconopsis grandis, the two species are geographically separated by a considerable distance. M. gakyidiana is almost a Bhutanese endemic found in the extreme east of the country and just over the border into Arunachal Pradesh and Tibet. The nearest M. grandis is much further west in west Sikkim, though even here the populations are sparse and it is essentially an east Nepalese species.
The status of plants in southern Tibet is very interesting, as they share characteristics of both M. grandis and M. gakyidiana.
If you are successful in establishing plants of both M. gakyidiana and M. grandis, be sure to grow them where they cannot inadvertently hybridise. It would however, be extremely interesting to cross pollinate a small proportion of your population deliberately under controlled and well documented conditions. As far as I know, nobody has yet done this successfully, though it would be good to hear from anyone who has.
