Red mulberry

"Volunteer" tree in a scrappy, urban, edge-of-the-parking-lot location, which would seem to incline toward white mulberry, but I feel pretty sure this is a red mulberry. Serrated leaf edges, non-shiny leaf tops and, as it turned out later, sparse fruit. Could be a hybrid, I guess. That's happening ... the hybridization of red mulberry with the more invasive white mulberry is, in fact, threatening the red mulberry. Hmm.