I'd be reluctant to hazard a guess as there is a wider range of hardy-for-our-climate Schefflera than one would expect. Dan Hinkley offers a half dozen different species through his Windcliff Nursery and sponsors a couple of Monrovia varieties as well. And Far Reaches Farms offers an equal number of other species as well. All apparently hardy to zones 7 (some) or 8.

Of the larger growing selections, these photos look most similar to Schefflera/Heptapleurum taiwaniana to my rarely actually seen and very untrained eye.