Japanese maple USDA PLANTS Symbol: ACPA2
U.S. Nativity: Exotic
Habit: Hardwood Trees Shrub or Subshrub
Acer palmatum Thunb.

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Taxonomic Rank: Magnoliopsida: Sapindales: Aceraceae
Native Range: Korea, Japan (REHD); Korea, China, Japan (BAIL);

Appearance
Acer palmatum can be grown as a multi-stemmed shrub or a single-stemmed small tree that can grows from 10-25 ft. (3-8 m) tall with a rounded to broadly rounded shape. The twigs have green and red, glabrous bark that is considered very showy. The bark on the trunk and main branches is gray.
Foliage
Acer palmatum has a palmate leaf that is from 2-5 in. (5-13 cm) across with from 5 to 9 lobes. The foliage is usually green with fall colors ranging from yellow, bronze, purple, orange to red. The beautiful fall colors are some of the reasons this tree has been used in landscaping. The cultivars of Acer palmatum vary widely.
Flowers
The small reddish purple flowers are carried in umbels. Acer palmatum blooms from April-June depending on the location. The flowers are beautiful close up, but are not usually very noticeable from a distance. Flowers are followed by winged fruit.
Fruit
The fruits of Acer palmatum are samaras. The fruits are elongated and usually range from 0.5-0.75 in. (1.3-2 cm) long. The covering of the fruit is dry and hard. The color of the fruit ranges from green to reddish green. Fruits ripen from September-October.
Ecological Threat
Acer palmatum is native to Japan, China and Korea. It is often used as a landscape ornamental plant. Acer palmatum can be found in yards, along roadsides, and streams. It has escaped cultivation, naturalised and is considered a weed in New South Wales and other parts of Australia. Acer palmatum has escaped and naturalized in the eastern United States and Hawaii, Canada and New Zealand. Widespread use of this plant increases the probability that more will escape from cultivation.

Identification, Biology, Control and Management Resources

Selected Images from Invasive.orgView All Images at Invasive.org


Foliage;
Jil Swearingen, USDI National Park Service, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage

Foliage; Tift County, GA
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage

Twig(s)/Shoot(s); Winter bud
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
John Ruter, University of Georgia, Bugwood.org
Additional Resolutions & Image Usage

Tree(s);
John Ruter, University of Georgia, Bugwood.org
Additional Resolutions & Image Usage

Cultivar; Acer palmatum 'Sango-kaku'
John Ruter, University of Georgia, Bugwood.org
Additional Resolutions & Image Usage

Cultivar; 'Dissectum'
Dow Gardens , Dow Gardens, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.

U.S. National Parks where reported invasive:
Rock Creek National Park (Washington, D.C.)



Invasive Listing Sources:
Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
Mid-Atlantic Exotic Pest Plant Council, 2005