Acer palmatum subsp. palmatum
Japanese maples are in fact Japanese in origin, occurring naturally in Korea and China as well. The low, mounded shape of the tree, along with its attractive color varieties and leaf varieties, have made it enormously popular throughout the world. Numerous cultivars are available.
Identification: These small trees do not exceed 25' (7.6 m) in height or width. Because they grow slowly, they often appear as rounded shrubs. Foliage may be purple or green. Leaves have 5-9 lobes, and are 1½-2½" (4-7 cm) around, with doubly serrated margins. Flowers are small, red or purple. Seeds are samaras ⅜-½" (1-1.5 cm) in size.
Acer palmatum on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Acer palmatum subsp. palmatum on Wikipedia
Acer palmatum on Erv Evans' site at the North Carolina State University College of Agriculture and Life Sciences
Acer palmatum at the University of Connecticut Plant Database
Acer palmatum subsp. palmatum at the Ohio State University PLANTFacts database
Acer palmatum subsp. palmatum description by Thomas H. Kent, last updated 16 Aug 2013.