gratrixianum has a dots on the dorsal petal
villosum had none :rollhappy:
Boxallii has dots on the dorsal as well, that's what makes it complicated sometimes, and the villosum from Nha Trang have dots too on their dorsal.
In fact, I think there are many evolving species from villosum to gratrixianum. However Boxallii is extremely rare in the wild nowadays, only recorded from Lao Cai area in Vietnam, and then from Burma/India for sure. The Chinese plants are plants collected in Vietnam.
Affine is coming from Vietnam too, in Gia Lai Kontum, I have seen some really massive plants of 'affine'. Affine is what is pictured here, and has narrower erect leaves. The 'true' gratrixianum has very wide leaves, some plants can be close to 60-80 cm, with leaves 5-6 wide, quite soft, and so far has never been used lately in breeding. It is possible that they used it as a 'villosum' or 'unknown parentage' for the early complex breeding... It would explain the spotting of some lineage of complex hybrids.
Affine is as well what has been used in the pot-plant trade under the name gratrixianum.
One famous pioneer of using affine for pot-plant is Prins Paphiopedilum. All of his breeding program used affine x complex hybrids. The reason is simple, affine blooms several times a year, and makes 2-3 new growths for each old growth. It clumps easily too, so it was the perfect parent to cross with slower growing, single flowered complexes. I have been very impressed by his breeding results, some being really very good with even several stems on a pot, and 2 flowers per stem - another trait that oddly enough affine passes to its progeny quite frequently, albeit affine very rarely has more than a flower/stem.