Ok....I was going to post my pic but Tony's is better and my plant came from him so its identical!
This is precisely why I started this post. The pics of white blanchetii and blanchetii are more similar to each other than to the prthenopipes shown in Tony P's pic.
My parthenopipes flower is identical to Tony's. *The source for material is also Best CP. *There seems to be significant differences between parthenopipes and white blanchetti in the flower structure (as shown by Vic and Sean). *Could this simply a problem with mislabelling or are these flowers two different forms of the same species?
Nothing needs so reforming as other people's habits.
The white blanchetii seems to have come into cultivation from seed collected by Fernando Rivadavia and grown by Lloyd Wix (see CP mailing list article here.
I would suspect that most of the specimens of "U. parthenopipes" in cultivation now are decendents of Lloyd Wix's plant.
According to Taylor, the distinguishing characteristics are flower size and the shape of the upper corolla lip:
Corolla 10-15 mm long, the upper lip wider than long, with apex retuse [rounded with a slight notch] = blanchetii
Corrolla 4-6 mm long, the upper lip as wide as long, with apex 3-crenate [cut into 3 scallops] = parthenopipes
The plant I have has flowers in the nebulous 6-10 mm range, but the upper corolla lip definitely indicates U. blanchetii and not U. parthenopipes.
It's always difficult to resolve taxonomic difficulties with plants in cultivation, where there is very limited variation. Perhaps we should just trust Fernando's judgement in the field.
N.B. Loyd Wix, not Lloyd
My "real" U. parthenopipes has flowered and it is definitely the real thing. The trick seems to be that upper corolla lobe. Just like in Taylor's key, it is as wide as it is long, and has two well defined notches, dividing it into three small scallops, the one in the center being smaller than the outer two. The flower is also about 5 mm long.