Amur corktree

(Phellodendron amurense)

Conservation Status

IUCN Red List

not listed

Amur corktree


NNA - Not applicable


not listed


Native to eastern Asia. Cultivated in Europe and Australia. Introduced in North America around 1856. Naturalized.


Adventive. Rare in Minnesota.


Moist but well-drained. Full to partial sun, but saplings are highly shade tolerant. Rich soil.


May to June

Flower Color



30 to 45



This is a moderate- to fast-growing, 30 to 45 tall deciduous tree rising on a single trunk from a wide-spreading root system.

The trunk is short and divided low into several large branches. The crown is broad and often flat topped.

The bark on young trees is light golden brown or yellowish-gray. On mature trees the bark is gray, thick, deeply furrowed, and slightly spongy or corky. Inner bark is bright yellow.

First year twigs are light green to green, hairless, slender, and round in cross section. They have white pith. Second-year twigs are brown, smooth, slender, and shiny, with scattered pale, raised dots (lenticels). Third-year twigs are slender and dull brown. They have tan pith. The leaf scars are large, raised, and U-shaped, almost encircling the bud. They have 3 groups of small bundle scars. The bud is concealed by the leaf stalk (petiole) until the leaf drops. It is brown, naked, broadly rounded, and covered by 2 brown, fuzzy, immature, scale-like leaves.

The leaves are deciduous, opposite, 10 to 15 long, and pinnately divided into usually 7 to 11, sometimes 5 or 13, leaflets. The petiole and central leaf axis (rachis) are light green, pale reddish-green, or almost white, and may be hairy or hairless. The rachis is slender.

The leaflets are lance egg-shaped to egg lance-shaped, 2 to 4¾ long, and 1 to 1¾ wide. They are rounded at the base and taper to a point at the tip with concave sides along the tip. The upper surface is dark green, shiny, and hairless. The lower surface is pale green and either hairless or hairy just along the veins. The margins are untoothed and have a fringe of short hairs. In autumn the leaves turn bright yellow.

Male and female flowers are borne on separate trees. They appear from May to June. The inflorescence is a loose, open and spreading, 2 to 3 long cluster at the end of a stem.

Each flower is about in diameter and is borne on a slender stem (pedicel). There are 5 sepals and 5 petals. The sepals are green or maroon, united at the base, and separated into 5 teeth at the tip. The petals are yellowish-green, united at the base, and separated into 5 lobes. Male flowers have 5 stamens with white filaments and bright yellow anthers protruding well beyond the petals. Female flowers have a pistil and 5 rudimentary staminodes that do not project beyond the petals.

The infructescence is loose, open, and spreading. Each fruit is a ¼ to ½ in diameter berry-like drupe with 5 seeds. It ripens from mid-June to mid-July. It is green at first, turning black when mature. The fruits remain on the tree until early winter.


Chinese corktree (Phellodendron chinense) branches, pedicels, and rachis are robust. The leaflets are broader, up to 2. The inflorescence and infructescence are compact. It has been reported only in Winona County.

Pests and Diseases


Distribution Distribution Map  

Sources: 2, 7, 22, 29.

There are only two reports of this species in Minnesota:

Carver County: 9/28/2007. Lake Minnewashta County Park. “Along east trail by first parking lot at top of hill. 4 - 5 scattered trees, 6-14" dbh. Also one tree along lakeside trail in park.” 44.8822, -93.5897.

Dakota County: 10/20/2015. Whitetail Woods Regional Park. One tree alongside and overhanging the hiking trail near the top of the hill. 10 to 12 dbh. 44 41.320, -93 5.345.


Amur corktree is considered a pest tree in New England. When allowed to become established it can create dense stands consisting of a large number of small trees that crowd out native species. It produces massive amounts of berry-like fruits which remain on the tree into winter. Seeds are spread by American Robins and other birds. It is reported to be invasive in scattered locations in Illinois, Maryland, Massachusetts, New York, Pennsylvania, and Virginia. It is a prohibited species in Massachusetts. It is not listed in Minnesota, probably because of its rarity in the state.



Rutaceae (rue)





Phellodendron japonicum

Phellodendron lavallei

Phellodendron sachalinense


Amur corktree

Chinese corktree








Bundle scar

Tiny raised area within a leaf scar, formed from the broken end of a vascular bundle.



A fleshy fruit with usually a single hard, stone-like core, like a cherry or peach; a stone fruit.



On plants: The thread-like stalk of a stamen which supports the anther. On Lepidoptera: One of a pair of long, thin, fleshy extensions extending from the thorax, and sometimes also from the abdomen, of a caterpillar.



A corky, round or stripe-like, usually raised, pore-like opening in bark that allows for gas exchange.



In plants: the stalk of a single flower in a cluster of flowers. In Hymenoptera and Araneae: the narrow stalk connecting the thorax to the abdomen.



The stalk of a leaf blade or compound leaf that attaches the leaf blade to the stem.



The main axis of a compound leaf, appearing as an extension of the leaf stalk; the main axis of an inflorescence.



An outer floral leaf, usually green but sometimes colored, at the base of a flower.



A modified stamen that produces no pollen. It often has no anther. Plural: staminodia.

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Furrowed Bark

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Rough Bark

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  Amur Corktree
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Other Videos

  How to ID Phellodendron amurense
Laura Deeter

Uploaded on Nov 19, 2008

Short video with the top identifying characteristics for Phellodendron amurense

  Chinese Herbs in America: Phellodendron - Clearpath SHM
Clearpath School of Herbal Medicine

Published on Apr 21, 2014

Wildcrafting Amur Cork Tree (Phellodendron amurense) in Northwest Connecticut. An under utilized Chinese herbal medicine now considered an invasive species in many parts of the U.S. This video focuses on properly identifying the tree in the wild among several lookalikes,and talks about the medicinal uses of the bright yellow inner bark.

  Eric Morgan Poster 2 - Botany 2010
Botany Conference

Uploaded on Aug 11, 2010

Determining the Invasive Capabilities of the Exotic Tree Phellodendron amurense Rupr. in Northeastern North America. Co-author: Jonathan Borysiewicz

Study of an introduced exotic tree species Phellodendron amurense Rupr. which has been used as an ornamental tree over the past century throughout areas of the Northeastern United States. Current research initiatives involve documenting and analyzing invasions of the tree into urban and suburban woodlands. Five study sites were chosen after careful survey of the pertinent literature, records of established northeastern herbariums, and responses from a 2008 request sent to botanical organizations and universities. Sites include data from 2 counties in Connecticut, 2 counties in New York, and 1 county in Pennsylvania. Field studies were conducted at each of the five sites using a variation of the Point-Center-Quarter method to determine the importance value of P. amurense within the forest. The results of this experiment indicate that P. amurense can invade multiple forest types and densities. The implications of this provide strong evidence for more research on the invasive abilities of P. amurense, strict management policies in areas that are already invaded, and nomination of P. amurense for listing in invasive plant databases (e.g. IPANE).




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Whitetail Woods Regional Park




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