P. aphrodite is usually confused by the other species -P. amabilis.
I spent almost over 6 months to learn that. But the best way is to grow some.
The ways to tell the differences are watching the callus and lip. If you have enough experiece, even can judge where it came from.
But remember most these white flowers came from Philippines are P. aphrodite. Only from the Palawan or some small islands near the Borneo are P. amabilis. On the other hand, most P. amabilis are from Malaysia and Indonesia.
There is another trouble species , P. aphrodite var. formosa, or P. amabilis var. formosa
. Recently the local university has made a study, in fact, it is different from P. aphrodite by DNA exam. That is why the Jappanese botanist gave it the indepent name of P. formosa in the past.
If you check these correct species together, it is easy to find the differeces, but the P. formosa has almost become extinct in the wild, so it is not so important or has enough prooves to correct the name now.