This is just conjecture, but here's what I think happened. The AHS version is the original, and someone, (presumably the hybridizer, but maybe the registrar) decided to wrap the entire parentage in one last set of parenthesis. This "Gift Wrapping" is something I see frequently in catalogs.
AHS:
(((Cerulean Star × Loch Ness Monster) × ((Fairy Tale Pink × Donetha Marie) × Enchanter's Spell))
Removing the end wrappers gives us the NGA version,
((Cerulean Star x Loch Ness Monster) x ((Fairy Tale Pink x Donetha Marie) x Enchanter's Spell)
which is unbalanced. My gut feeling is that there is one remnant, erroneous parenthesis on the left, which, if removed, leaves us with;
(Cerulean Star x Loch Ness Monster) x ((Fairy Tale Pink x Donetha Marie) x Enchanter's Spell)
which would mean that the SC x LNM seedling was the pod parent, and the (FTP x DM) x ES seedling was the pollen parent.
However, since it's a botched parentage to start with, it's "possible" that it's really this;
((Cerulean Star x Loch Ness Monster) x (Fairy Tale Pink x Donetha Marie)) x Enchanter's Spell
where Enchanter's Spell was the finishing pollen. Possible, except for; 1) it requires a lot more manipulation in order to make it so, (Occam's Razor) and 2) Edge of Chaos is a 7" UF, which is an improbable (not impossible) result if a 3" diploid was the direct pollen parent.
Regarding "X vs. x", It seems to me that it only works once. In other words, in order for it to be effectively used as I think it's intended—to indicate the "final" pollen parent, or "final" pairing—that would seem to mean that there's only room for one large X in a parentage "equation". The question is, what happens in subsequent generations? Even though the parentheses may seem to be difficult to sort out, I still believe that if done correctly, they're the best thing going with regard to plants with long, complex lineage.
)))
Still, using the upper case form would tell you instantly which cultivars belong on the pod side and which belong on the pollen side.
. Your parentheses are balanced. The way you wrote it with the upper case X makes it clear that the parentage consists of a seedling for the pod parent and another seedling for the pollen parent. The only reason I would add an extra parenthesis on the pollen parent would be to denote it as one plant. It obvious, but visually it would just be easier for me. How did you know where that upper case 'X' belonged? In the intital post, I couldn't really tell if it went there or if it went before Enchanter's Spell and the pod parent was actually a cross between two seedlings.
. If you use multiple generations of unregistered seedlings, it gets complicated. So a subsequent cross using the plant registered as Edge of Chaos would be ((Cerulean Star x Loch Ness Monster) x ((Fairy Tale Pink x Donetha Marie) x Enchanter's Spell)) X Whatchamacallit. Obviously this would only apply to unregistered seedlings or seedlings used prior to registering and introducing when they are used as a parent.
