King Palms are actually a group of species within the genus of Archontophoenix. As discussed below there are six different species in this genus and all are from Australia. There are differences between all of these speciesand this includes overall size and appearance, color of the crown shaft, the undersurface of the leaflets, seeds and flower traits. From a landscape point of view, King palms are very popular and planted widely throughout the world. But, the most common species, Archontophoenix cunninghamiana, is the only species most gardeners and even some landscape architects are familiar with. When the gardener says "King Palm", it's thecunninghamiana that he's referring to.