Japanese maple
(Acer palmatum)
This species is Introduced in the United States
Appearance
Acer palmatum can be grown as a multi-stemmed shrub or a single-stemmed small tree that can grow 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, naturalized, 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.
Citation
Rawlins, K.A., R.L. Winston, C.T. Bargeron, D.J. Moorhead, and R. Carroll. 2018. New Invaders of the Northeast and Northcentral United States. USDA Forest Service, Forest Health Assessment and Applied Sciences Team, Morgantown, West Virginia. FHTET-2017-04. Retrieved from https://bugwoodcloud.org/resource/pdf/FHTET-2017-04_New%20Invaders_NE.pdf
Selected Images
Maps
EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State Lists - This map identifies those states that have this species on their invasive species list or law.
Invasive Listing Sources
- Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
- National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
- New Invaders of the Northeast and Northcentral
- New Jersey Invasive Species Strike Team 2017 Invasive Species List
- Non-Native Invasive Plants of Arlington County, Virginia
- Pennsylvania Department of Conservation and Natural Resources Invasive Plants
- WeedUS - Database of Plants Invading Natural Areas in the United States
Taxonomic Rank
| Domain: Eukarya |
| Kingdom: Plantae |
| Phylum: Magnoliophyta |
| Class: Magnoliopsida |
| Superorder: Rosanae |
| Order: Sapindales |
| Family: Sapindaceae |
| Genus: Acer |
| Acer palmatum |
References
Common Name Reference: USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.
Scientific Name Reference: USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.