Paphiopedilum callosum is accepted species in  the family Orchidaceae  subfamily: Cypripedioideae,  
Genus Paphiopedilum   subgenus Sigmatopetalum  subsection: Barbata 
Infraspecific taxa recognized within Paphiopedilum callosum: infraspecific taxa
This species is found in Indo-China to NW. Pen. Malaysia.