Acer paxii Franchet
This relatively rare tree is from southwestern China. It was discovered by P. Delavay in 1883, and later named for German botanist Ferdinand Albin Pax.
Identification: Trees are up to 49' (15 m) tall. Leaves have three lobes or none at all, and are 1¾-4" (5-11 cm) × ¾-2" (2-6 cm). This is an evergreen, while most maples are deciduous. Seeds are winged as with other maples, but purple. Not found in the wild in North America. See Acer for a comparison chart.
Acer paxii on eFloras
Acer paxii at the Urban Forest Ecosystems Institute's SelecTree site (good photos)
Acer paxii on the University of British Columbia Botanical Garden & Centre for Plant Research forums
Acer paxii description by Thomas H. Kent, last updated 16 Aug 2013.