Can anyone identify this plant? It was purchased in southern Oregon.
It's Berberis thunbergii atropurpureum, maybe 'nana', the dwarf version with a height of around 50 cm or the larger version which gets around a metre and a half planted in the ground. It's deciduous, and needs to be kept outdoors with at least 3 or 4 hours direct sunlight - without sun, the leaves will turn plain green. It will need protection from temperatures below -5degC, so plan to move indoors to a very cool room briefly or into a greenhouse until temperatures rise again, but don't keep it inside any longer than you have to. More info here http://www.bonsai4me.co.uk/SpeciesGuide/Berberis.html