Quick Facts

Quick facts

• Originally from China, Korea and Japan, Chinese Celtis (Celtis sinensis) is now a serious environmental weed in south-east Queensland and north-east New South Wales.
• It was introduced as an ornamental and shade tree and old trees in gardens are a major source of seed spread to bushland.
• The seeds are spread by fruit-eating birds, fruit bats and water.
• It forms dense thickets in disturbed riparian sites and prevents the regeneration of indigenous flora.
• Control of this weed requires coordinated use of manual and chemical methods including removal of old established trees in gardens.

What Does It Look Like?

What is it?

Chinese Celtis (Celtis sinensis) is a deciduous shrub or tree to 15m (rarely to 25m) high with smooth silvery-grey bark. The leaves are 4–10 cm long, 2–4.5 cm wide, dark green with prominent veins, and are more or less oval in shape with the base attaching to the leaf stalk asymmetrically. The leaf margins are toothed in the upper half only. The upper surface is shiny and mostly hairless; the lower surface is paler than the upper with hairs on veins. Leaves emerging at flowering are initially hairy, particularly below, but rapidly become almost hairless.

The inflorescence consists of few flowers, with the upper flowers bisexual and lower flowers male. Each flower has four sepals which are purplish on their outer surface, about 2.5 mm long and 1 mm wide and wider than the enclosed petals. There are four cream petals as long as the sepals and four stamens. Flowers appear from late winter to early spring.

The mature fruit is globe-shaped, orange or orange-brown, 6-8 mm long and is borne on a stalk 4 to 10 mm long (Harden & Murray 2000; Weeds Australia undated).

For further information and assistance with identification of Chinese Celtis contact the herbarium in your state or territory.

Flower colour

Cream

Growth form (weed type/habit)

Tree, Shrub

Where it currently grows? Preferred habitat

Chinese Celtis is a widespread weed in damp coastal areas, particularly along banks of waterways and near rainforest (Harden & Murray 2000; Weeds Australia undated). It favours disturbed sites (Land Protection 2006) and is commonly found on clay soils (Weeds Australia undated).

Are there similar species?

Chinese Celtis (Celtis sinensis) may be confused with Chinese Elm (Ulmus parvifolia), Nettle Tree (Celtis australis), Hackberry (Celtis occidentalis) and the native Silky Celtis (Celtis paniculata). The main differences are in leaf size, margins and the fruit (Navie 2004).

Chinese Celtis (Celtis sinensis) has relatively broad leaves with scalloped margins (particularly in the upper half) and a dark orange or reddish-brown coloured slightly fleshy (succulent) berry-like fruit. 

Chinese Elm (Ulmus parvifolia) has narrower leaves with finely toothed margins and dry fruit that have a flattened wing. 

Nettle Tree (Celtis australis) has relatively broad leaves but with sharply toothed (serrate) margins (particularly in the upper half) and a dark purplish or almost black coloured slightly fleshy (succulent) berry-like fruit. 

Hackberry (Celtis occidentalis) has relatively broad leaves with serrate margins (particularly in the upper half) and orange-red or dark purplish coloured slightly fleshy (succulent) berry-like fruit. Silky 

Celtis (Celtis paniculata) has leaves with entire margins and blackish-coloured slightly fleshy (succulent) berry-like fruit (Navie 2004).

Why Is It A Weed?

What are its impacts?

Chinese Celtis was included in the list of 71 species that were nominated by state and territory governments for assessment as Weeds of National Significance (WONS). Following an assessment process, Chinese Celtis was not included as one of the 20 WONS. However, it remains a weed of potential national significance. a weed of waterways and riverbanks (i.e. in riparian areas), roadsides, urban bushland, open woodlands, rainforest margins, waste areas, disturbed sites, parks and gardens in sub-tropical and warm temperate regions (NSW DPI 2019).

Agriculture: Chinese Celtis is a large, invasive tree that has become an environmental weed and a potential weed of agriculture because of its ability to become structurally dominant.  It may impede stocks access especially to waterways.

Native ecosystems: Previously cleared, regenerating riparian sites, and widespread along the north coast of New South Wales and the south coast of Queensland. Such sites are ideal for weeds such as Chinese Celtis, and for the frequently associated Camphor Laurel. Chinese Celtis is quick growing, even in dry conditions, and can rapidly form dense thickets that dominate river bank vegetation and prevent the regeneration of indigenous riparian species and negatively affect associated indigenous fauna through habitat destruction (Land Protection 2006). Dense infestations of Chinese Celtis also have the potential to impact on agriculture by competing for scarce irrigation water and moisture for crops and pastures (Armstrong & Keegan 1996).

How does it spread?

The seeds of Chinese Celtis are spread by birds, fruit bats and water (Weeds Australia undated). Fruit-eating birds that feed on it also feed on the fruit of the extensively naturalised Camphor Laurel (Cinnamomum camphora) and spread both weed species together to the disturbed riparian zones where they both thrive. Twenty bird species are reported to eat Camphor Laurel fruit and all of these birds can potentially spread Chinese Celtis (North Coast Weeds Advisory Committee 2004).

What is its history in Australia?

Chinese Celtis was introduced into Australia as an ornamental and shade tree. The exact date and place of its introduction is unknown. The earliest cultivated records dated from 1912 in Queensland and it was promoted as an excellent town street tree in the 1940s (Forster 2006). It was planted around Kyogle, New South Wales, at least 50 years ago (Enseby 2002).

How To Manage It?

Best practice management

Seedlings of Chinese Celtis under 30 cm high can be hand pulled or dug out (Armstrong & Keegan 1996; Land Protection 2006). Large trees may also be cut down and the stump dug up and removed (Enseby 2002). A major source of seed spread into urban bushland is from old mature heavily fruiting trees planted many years ago in private gardens. It is important that these trees are identified and removed (North Coast Weeds Advisory Committee 2004).

Chemical control: Various herbicides are registered for the control of Chinese Celtis. Methods recommended include stem injection for plants up to 30 cm basal diameter, application to basal bark for young plants up to 2 m high and 20 cm basal diameter, application to cut stumps, spot spraying for young plants less than 2 m high and foliar spraying of seedlings. See Armstrong and Keegan (1996) and the North Coast Weeds Advisory Committee (2004) for details.

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au

Non-chemical control: Manual removal of isolated small seedlings can be attempted by hand pulling or digging them up. This is only practical for a small number of plants. Large trees may be cut down and the stump dug up and removed. Care should be taken to avoid moving fruit to un-infested areas when manually removing mature trees.

Due to the associated spread of Chinese Celtis and camphor laurel into disturbed riparian areas, it is important that control of both species is undertaken concurrently. Otherwise one will replace the other (North Coast Weeds Advisory Committee 2004).

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

In northern New South Wales Chinese Celtis is deciduous or semi-deciduous in late winter and early spring (North Coast Weeds Advisory Committee 2004). Flowering takes place at about the same time (Weeds Australia undated). Unripe green fruits are present in spring and summer. Fruits turn orange, orange brown or reddish brown when ripe in autumn and early winter (Harden & Murray 2000; North Coast Weeds Advisory Committee 2004; Weeds Australia undated).

Where Is It Found?

Which states and territories is it found?

NSW, QLD

What areas within states and territories is it found?

Chinese Celtis is strongly naturalised in south-east Queensland where expansion has been rapid in recent years into riparian zones in the Sunshine Coast hinterland and around Ipswich. It is also naturalised in north-east New South Wales where old ornamental plantings in a number of urban areas act as seed source (North Coast Weeds Advisory Committee 2004).

Where does it originate?

Chinese Celtis is native to China, Korea and Japan (POWO 2021)

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

NSW, QLD, WA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Celtis sinensis

Other scientific names (synonyms)?

Does it have other known common name(s)?

Celtis, Chinese Elm, Hackberry, Japanese Hackberry