Its parents come from Indonesia, but this paph speaks with a Picksburgh accent. According to its tag in the Orchid Room at Phipps Conservatory, it has won an Award of Merit from the American Orchid Society.
Papihopedilum Transvaal is an old hybrid, first made in 1901, between P. chamberlainianum and P. rothschildianum. Orchid genetics are complex enough that the seedlings from a hybrid are all different, so each one can become a named clone (with the name in single quotes) if someone likes it well enough. Obviously, with AM-AOS after its name, someone would like this one a great deal.