Well, the status of the variety seems to be somewhat debatable: although Kew accepts it as a good variety - other authors actually questions its taxonomic status. Cribb seems to present an almost split personality, as Kew cites him as one of the sources for the variety (1998), while at the same time refers to another publication, that he co-authors, that does not accept the variety (Pedersen, H.Æ., Kurzwell, H., Suddee, S. & Cribb, P.J. (2011). Flora of Thailand 12(1): 1-302. The Forest Herbarium, National Park, Wildlife and Plant Conservation Department, Bangkok. [Cited as Paphiopedilum callosum var. warnerianum]).
Averyanov in a review of P. callosum varieties in Vietnam discusses the variety under the name var. warnerianum, too. He describes it as "...distinctly smaller than flowers of type variety. Their petals are regularly broad and spread, without warts along the lower margin. Coloration of flowers varies from light pink/green to deep purple". However, he, without specific reference to other authors, mentions, that the variety "... is sometimes regarded as an “intermediate” hybrid form between two vicarious species—P. callosum (distributed in mainland Southeast Asia) and P. barbatum (from Malacca Peninsular and northern Sumatra)". Overall on the callosum-varieties, he remarks: "On the basis of our observations, it looks as if these varieties merge into one another with more or less numerous intermediate forms".
I found Averyanov's article so interesting - and containing loads of wonderfull photos of a broad range of P. callosums, that I have attached it here as a file.
PS. Judging from the photos, the flowers of Fiona's wonderfull plant seem to grow in size as the plant matures. What to make of that?!
