Paphiopedilum nigritum 'Thommen Extra', April 1970, roll 197004 slide 3. Species described in 1894.
Paphiopedilum nigritum 'Thommen', April 1970, roll 197004 slide 5. Species described in 1894.
Paphiopedilum nigritum?, [Ray Rands collection number] R68U3, June 1968, roll 196806H6 slide 9. Species described in 1894.