Good morning, nothing like a good Phrag. thread to enjoy with the morning coffee.
The correct name for this plant is warszewiczianum. Notwithstanding a lot of confusion surrounding other names in the genus, there really is no confusion as to the name of this species and all the publications in the past 15 years or so agree the name is warszewiczianum (Cervera, Gruss, Cribb, Braem).
What happened was, this species was formally described in the mid 1800's as warszewiczianum. After that, the description was lost, overlooked or ignored, and this species was thereafter described as wallisii. It was known by the name wallisii for decades. There are hybrids registered with that name and awards in the database.
When the error was discovered, the name was formally changed back to warszewiczianum, and according to the rules, this is exactly what should have happened and there is no modern disagreement on this point nor the correct name for the species.
What we need to be careful of, and we being the phragmipedium community, are dubious commercial sources continuing to use the name wallisii in hybrid registrations and on their sales bench (I saw a tag earlier this year that read 'Phragmipedium wallisii variety warszewiczianum forma wallisii, no kidding).
Kudos to Rich for providing a simple and easy to understand way of deciphering the species in this group. Thanks Rich.
Best,