Trees, Shrubs and Conifers: Purple plum tree or purple leaf sand cherry?, 0 by Cearbhaill

Cearbhaill wrote:
Yet another question from the newbie to the zone :)

I see that purple leaf sand cherry is Prunus cistena and purple plum tree is Prunus cerasifera. OK.
But I have a plant whose tag reads Ciruela Cistena de Hojo Morada "purple plum tree" and upon searching I am just getting more and more confused.
What is it??
Are they one and the same?
And if so- I understand the failings of common names but a cherry is not a plum!!
Or is it?

Don't laugh at the beer bottle photo- I sent the husband out to take plant photos and this was his way of providing size comparison.