I had suspected that Fantasy Kingdoms was a fairly new game and this was confirmed when I visited their page on Facebook and read an announcement to the effect that the game was celebrating its three month Anniversary.
New options appear constantly in Fantasy Kingdoms but I was saddened to discover that Items may be discontinued without notice as well. I should have understood, however, that the Sunflower was a part of the Summer Solstice Collection and there were many notices to the effect that those items were temporary editions.
Ordinarily, in real gardens, I am not terribly fond of Yellow or Orange Flowers. The Sunflower is NOT a personal favourite in the 'real world'. I believe the reason for this is my dislike of heat in Summer. As the Summer heat becomes unendurable, the season of the Sunflower and other Yellow and Orange Flowers begins and the Purple and Blue Flowers of late Spring that are my favourites tend to wither away or disappear. In Fantasy Kingdoms, however, the Sunflower is one of my favourite Crops/Flowers. Its luminous sun-like golden Lamps makes any Kingdom breathtakingly beautiful. When Enchanted (fertilised) by a Neighbour, they become larger and even more stunning.
Alas, I no longer can find the Magical Potion (Seeds) for the Sunflowers at the Market. As of yesterday, they appear to have been discontinued, at least for the time being.