Many references use Feijoa sellowiana as the scientific name for this South American species, but it has generally been accepted to be Acca sellowiana since 1941 (see discussion on this thread, though note that the plant being identified is not Acca – the discussion just veered to a different topic). It’s an example of a how a species name can become entrenched and difficult to change in the minds of many people. This is particularly likely to happen when a plant is of economic importance (if I’m allowed to make such a generalization), as is the case with Acca sellowiana.
Feijoa, as it remains commonly known (and adding to the entrenchment of the synonym), is grown primarily for its edible fruit, which is purported to taste like a combination of pineapple and strawberry or pineapple and guava. I haven’t sampled it, but it’s on my list of things to try. More economic and other information about this species is available from the Plants for a Future Database and the California Rare Fruit Growers.
Botany resource link: Diversity, Endemism, and Extinction in the Flora and Vegetation of New Caledonia, a paper by Porter P. Lowry II of the Missouri Botanical Garden. The online article contains a number of photographs of plants seen nowhere else in the world.