Phragmipedium caudatum

caudatum is often mislabeled and a few things have been grouped together as such. Naoki can elaborate further on the distinctions between varieties. Your's is very interesting and very well grown. The colors are quite pale but together they make a stunning combination. It certainly has the cleanest pouch I have seen. The white just pops. Congrats regardless.
http://slipperorchids.info/phragdatasheets/caudatum/index.html

 

It looks like var. wallisii

 

I agree with Chad. The edge of the lip opening looks like P. wallishii Take a look at the fig. 3 of

http://www.epidendra.org/taxones/Ph... 2011 - Phragmipedium sect. Phragmipedium.pdf

 

So much going on with such a simple colour scheme. Great photos.

 

Lisa, do you happen to know which aspects of the flowers indicate possible hybrids? I'm recently interested in this group, so I don't know much, and I'd like to learn about how to tell the hybrids.

I thought that the taxonomy of this group isn't well settled yet. Different people thinks differently about which ones are given at the species rank. In addition to that, the interpretation of original description and priority is quite a bit of mess. My understanding is that P. popowii (aka P. humboltii) is the name given to the ones from Central America by Dr. Braem (2004). I thought that he considered that what was known as P. walishii (from around Ecuador) is a separate species, and it should be called P. warszewiczianum (which was commonly used for P. popowii/humboltii). So I don't think he considers these two species are synonymous. There are lots of discussion about this in ST, but it becomes more confusing after reading all the info... Here is an example.

 

Great photos!