It did seem strange that a species I had had no luck with growing in the past could be doing so well and acting strangely dominant and exclusionary in the local wilds. A quick look in Michael Dir's hefty Manual of Woody Landscape Plants showed distinct differences.
They have similar flowers--both are in the rose family--but native Red Chokeberry blooms a few weeks earlier, with Photinia blossums opening in mid to late May.
The petiole (segment connecting leaf to stem) is 1/8th inch on Photinia, longer on Chokeberry. The leaf venation pattern too is different.
Fall color is tan, while Red Chokeberry is said to be red. Photinia also grows much larger, reaching 15 feet or more.
Results from an internet search suggest that I'm not the only one who has been unaware. The USDA government site shows it growing in three states plus DC, but not in NJ. A University of Florida site says it has little invasive potential.
Thanks to Jared Rosenbaum, of D&R Greenway, for alerting me to the presence of this invasive.