The thorns sound right, Henry, although one of the seedlings I have is almost thornless.
Species roses are supposed to be more or less self sterile so it is possible that the bees contributed to your seedling and/or to my mother plant as my species roses were raised from seed.
Tomorrow I am planning on planting out more seedlings. I will be on the lookout for variations.
I should mention that in that bed I had only the diploid form of R. acicularis - nipponensis.
I just looked on your web page, Henry. The leaves in your picture of R. acicularis nipponensis sure look the same as mine.
Thanks Judith for pointing out that I had the pictures posted (I had forgotten about them).
For others who received the seeds, the pictures can be found at:
http://home.neo.rr.com/kuska/R.acicularisnipponensis.htm
Note, if some of your seeds germinated at a different time frame, you may have some of the actual (Heritage X William Baffin) X OP seedlings since I assume that some of the hips that I picked were from the correct plant. It is also possible that the actual (Heritage X William Baffin) X OP seeds have not germinated yet since my germination stopped quite a while ago and I still have a lot of seeds left.