Delavay's schefflera or sui xu e zhang chai is native to southern China and northern Vietnam. Most people in the temperate world have encountered the genus Schefflera as a houseplant, e.g., umbrella tree, dwarf schefflera and false aralia. The widespread cultivation of these subtropical and tropical members of the genus as indoor plants is now slowly being supplemented by the introduction of a few hardier, temperate species (such as Schefflera delavayi) for use as outdoor plants in mild climates. The plant in today's photograph weathered last year's locally cold temperatures with no ill-effect. It is currently in bloom in the David C. Lam Asian Garden (this photograph is from mid-October of last year).
There seems to be some confusion about the identity of Schefflera delavayi on the web. The plant in this photograph does seem to conform to the Flora of China description of Schefflera delavayi. A search on the web, though, will reveal a few nursery sites showing a seemingly different species with oak-like leaves. I'm not certain of the origin of this confusion.
In the wild, Schefflera delavayi will grow to 8m (26 ft.). Our specimen at UBC Botanical Garden is still under 2m.