Amur maple (Acer ginnala)

Synonyms: Acer tataricum subsp. ginnala, Acer tataricum var. ginnala

Common Names: Siberian maple, Ginnala maple

Description:

Amur maple (Acer ginnala) is a small tree from northeastern Asia, brought to North America in the 1860s as an ornamental and windbreak plant prized for its brilliant red fall color [1]. It has since escaped from yards and plantings into the wild [1]. MISIN tracks it because it seeds heavily, forms dense shade, and crowds out native shrubs, wildflowers, and grasses in open woods, prairies, and savannas [1][3].

Habit:

Amur maple is a small, often multi-stemmed tree or large shrub that grows up to about 20 feet tall [1][2]. Its leaves grow in opposite pairs and have three lobes, with the middle lobe noticeably longer than the two side lobes, and finely double-toothed edges [1]. The leaves are longer than they are wide, roughly 1 to 4 inches long [1][2]. In fall they turn a brilliant red ? the trait that made it a popular landscape tree and the easiest time of year to spot it standing out along a wood edge or roadside [1]. In spring it bears small, fragrant yellowish-white flower clusters, and by late summer it hangs heavy with paired, often reddish winged seeds whose wings sit at a tight, nearly parallel angle [1][2].

At-a-glance cues:

1. Opposite, three-lobed leaves with the middle lobe longer than the sides and doubly toothed edges [1]
2. Brilliant red fall color on a small, often multi-stemmed tree up to ~20 feet [1]
3. Paired winged seeds (samaras), often reddish, with wings set at a tight, nearly parallel angle [1]
4. Cut or damaged stems resprout readily from the stump [1]

Leaves:

1. Arranged in opposite pairs along the twig [1]
2. Simple, with three lobes; the middle lobe is distinctly longer than the two side lobes [1]
3. Edges finely double-toothed (doubly serrate) [1][2]
4. About 1 to 4 inches long, longer than wide; turn brilliant red to orange in fall [1][2]

Stems:

1. Woody; grows as a small tree or large shrub up to about 20 feet, often with several trunks [1][2]
2. Bark is thin, gray-brown, and smooth when young, becoming shallowly furrowed and striped with age [2]
3. Twigs are slender and light-colored [1]
4. Resprouts vigorously from the stump when cut [1]

Flowers:

1. Small, yellowish-white, and fragrant [1][2]
2. Borne in loose branched clusters (panicles) [2]
3. Appear in spring, roughly April to June, as the leaves emerge [1]
4. Each flower has both male and female parts [2]

Fruit and seeds:

1. Paired winged seeds (samaras), the typical maple "helicopter" fruit, up to about 1 inch long [1][2]
2. Often reddish, with the two wings set at a tight, nearly parallel angle [1]
3. Ripen in late summer and fall and may hang on the tree into late fall [1][2]
4. Carried by wind; the tree is a prolific seed producer and the seeds germinate readily [1]

Habitat:

Amur maple turns up along forest edges, roadsides, and fencerows, and in open woods, prairies, savannas, early-growth forests, and other disturbed ground [1]. It tolerates shade, which lets it move in under existing trees as well as in the open [1]. It handles a wide range of soils and is widely planted in yards and along streets, which serve as the seed source for wild spread [1]. It is native to northeastern Asia ? mainly northern China and Japan and nearby areas ? and was introduced to North America as a landscape and windbreak tree [1][3].

Reproduction:

Amur maple spreads mainly by seed [1]. Each tree can produce large numbers of winged seeds that spin away on the wind and sprout easily, so a single planted tree in a yard or park can seed nearby woods, fields, and roadsides [1]. It also comes back stubbornly from the base: when a stem is cut or broken, the stump resprouts with vigorous new shoots [1]. That makes it persistent once established and means cutting alone often is not enough.

Seeds ripen in late summer and fall and blow off the tree into late autumn [1]. For control, timing matters ? remove or cut trees before the seeds ripen and drop, and plan to return for the resprouts and seedlings that follow [1].

Impact and Damage:

Amur maple is not poisonous and is not a structural or garden pest in the usual sense ? the trouble is how aggressively it escapes and how hard it is to remove once it has seeded into natural areas [1]. Where it takes hold it forms a dense canopy that casts heavy shade; in invaded Minnesota woodlands, stands of Amur maple let as little as 2% of sunlight reach the ground, which strongly suppressed nearly all other plants beneath them [3]. By shading the ground this way, it displaces native shrubs and understory trees in open woods and shades out native grasses and wildflowers in prairies and savannas, lowering overall plant diversity [1][3]. It can convert open, sunny prairie and savanna into shaded shrubland or woodland ? a wholesale change in habitat [1]. Its seeds also release chemicals that can suppress the growth of competing plants, which may add to its edge over natives [3].

Similar species:

Amur maple is a maple, so it is most often confused with other maples. The opposite, three-lobed leaves with a long middle lobe and the tight, nearly parallel seed wings are the best clues.

Tatarian maple (Acer tataricum) is its closest relative ? so close that Amur maple is often treated as a subspecies of it ? and is also a non-native invader. Its leaves are usually unlobed or only shallowly lobed, while Amur maple's leaves have three clear lobes with a long middle lobe [1].

Mountain maple (Acer spicatum) is a native shrubby understory maple with a similar small, multi-stemmed habit and three-lobed, toothed leaves. Its leaves are more coarsely toothed and softer-looking, and its flower and seed clusters stand upright, unlike Amur maple's fragrant spring clusters and nearly parallel seed wings [1].

Red maple (Acer rubrum) is a common native tree with red fall color and reddish seeds, which causes confusion. But its leaves are larger with three to five lobes separated by shallow notches, and it grows into a full-size single-trunk tree rather than a small multi-stemmed one [1].

Trident maple (Acer buergerianum) is another non-native ornamental with three-lobed leaves. Its leaves have smooth or only slightly toothed edges and a glossy surface, while Amur maple's leaves are clearly double-toothed [2].

Monitoring and rapid response:

Signs to watch for:

1. A small, often multi-stemmed maple with opposite, three-lobed, double-toothed leaves [1]
2. Brilliant red fall color standing out along wood edges, fencerows, and roadsides in autumn [1]
3. Paired reddish winged seeds with nearly parallel wings in late summer and fall [1]
4. Seedlings and saplings spreading outward from a planted yard or street tree [1]

What you can do:

1. Pull or dig out seedlings and small plants, getting the roots; this is easiest in moist soil [1]
2. For larger stems, cutting works only if you expect resprouting ? plan to cut the regrowth again, or girdle (remove a ring of bark from) larger trunks, and check back over a couple of seasons [1]
3. Remove or cut trees before the seeds ripen and drop in late summer, and bag and dispose of seed-laden branches [1]
4. Do not plant Amur maple, and remove existing yard or street trees that are seeding into natural areas [1]
5. Natural area crews can cut or girdle larger trees and revisit for resprouts, and should target seed-source trees and small outlying plants first before they spread [1]

When to call a professional:

1. Large trees or dense stands that resprout aggressively after cutting [1]
2. Established infestations across a woodland, prairie, or savanna where coordinated removal is needed [1][3]
3. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. Minnesota Department of Natural Resources. Amur maple (Acer ginnala) and Tatarian maple (Acer tataricum). dnr.state.mn.us
2. North Carolina State Extension Gardener Plant Toolbox. Acer tataricum subsp. ginnala (Amur Maple). plants.ces.ncsu.edu
3. Schuster MJ, Reich PB (2018). "Amur maple (Acer ginnala): an emerging invasive plant in North America." Biological Invasions 20(10):2997?3007. semanticscholar.org

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