I remember distributing a plant labeled P.moranensis var. caudata "Longwood" that I received from a LACPS meeting. Right now, the plants are mass flowering for me, and I have to say that the flowers indicate this plant is in fact P.'Sethos'. I have a plant of P.'Sethos' from CC that is starting to produce flowers. I will compare the two for a more accurate id. Sorry for the confusion.
On a side note, after moving my entire collection of pings to an outdoor setup, I am noticing that much more plants are flowering. Some of my plants like P.ehlersiae(normal and alba), debbertiana var. pink flower, ehlersiae cv. Harold, gigantea, agnata(couple different forms), moranensis(couple different forms), gracilis,'Aphrodite' etc. only flowered after I moved them outdoors. I could not get my P.ehlersiae to produce flowers for almost 2 years inside the house(these were 2in diameter and mature). I believe that the combination of brighter lights, and cooler night temperatures(high 40's-mid 50's) caused the plants to flower.
Also, some of my pings(especially moranensis) would abort their flowers in my indoor setup. This has not happened outdoors(much better air circulation and less humidity).
Some of my pings(like potosiensis) produced flowers that were pale purple with heavy veining when they were grown indoors under lights. When I moved the potosiensis outdoors, the flowers produced were much darker, and the veins were barely noticeable(like the pics of potosiensis on the net). The leaves of my P.agnata are more red, much more thick, and they press flat against the substrate(grown outdoors). I can see how id confusion can result...