Cecropia (Cecropia species)

Also known as: Mexican bean tree

Cecropia is a fast-growing tree with large lobed leaves. It invades coastal forests and riparian areas and competes with native plants.

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How does this weed affect you?

Cecropia grows quickly and can form dense stands in disturbed areas, wet forest edges and riparian zones where it:

• outcompetes native plants
• prevents regeneration of rainforests.

What does it look like?

Three species of cecropia have been recorded in Australia (Cecropia pachystachya, C. palmata and C. peltata). These species grow between 5–40 m tall and most of the leaves are usually on the upper part of the tree. The bark is smooth and grey.

The following descriptions are for Cecropia peltata, which is the only species that has naturalised in NSW and Cecropia palmata which has been found in Queensland. They usually grow 10 m–20 m high but occasionally up to 25 m and with a trunk up to 50 cm. 

Leaves:

• are dark green on top and usually white or grey underneath
• are up to 60 cm long
• of C. peltata have 7–11 lobes with pointed tips 
• of C. palmata have 9–15 deep lobes
• are hairy, more so on the underside
• attach to a 0–50 cm long a stalk 
• are wrapped in a green to brown leaf sheath approximately 15 cm long before they unfurl
• are alternate along the stem.

 Juvenile leaves of C. peltata are much smaller and often without lobes.

Flowers:

• are tiny and very close together on cylindrical finger-like spikes
• are either female or male flowers are on separate trees.

 Male flowers spikes are:

• in clusters that are erect or bent downwards,
• yellowish
• up to 12.5 cm long for C. peltata with 12–50 spikes per cluster
• up to 18 cm long for C. palmata with 3-9 spikes per cluster.

Female flower spikes are:

• in erect or drooping clusters
• greenish or greyish-green
• 1–4 cm long for C. peltata with 3–5 spikes per cluster
• 17–30 cm long for C. palmata with 2–6 spikes per cluster.

Fruit are:

• small (3–4 mm long)
• fleshy
• inconspicuous
• in cylindrical clusters 9-12 cm long.

Seeds are:

• brown
• oval-shaped
• around 2 mm long.

Stems:

•  have obvious triangular or crescent-shaped scars left behind when old leaves fall of
• are often hollow when young
• have a watery, milky or jelly-like sap that turns black when exposed to air
• sometimes have numerous small holes or pores.

Roots:

Large plants may have stilt roots that protrude from the trunk up to a metre above the ground.

Similar looking plants:

Cecropia looks like:

• Umbrella tree (Schefflera actinophylla),which does not have lobed leaves. It has red to purple flowers and fruit and only grows up to 10 m tall.
• Pawpaw (Carica papaya), which has smooth green leaf undersides, white or cream flowers with 5 distinct petals, green to orange football-shaped fruit and grows to 10 m
• Castor oil (Ricinus communis), which has smooth green leaf undersides, red and yellow ball-shaped flower clusters, and usually grows to 3 m tall (but sometimes up to 12 m).
• Rice paper plant (Tetrapanax papyrifer), which has hairy leaf undersides, numerous, ball-shaped clusters of white flowers and grows to 4 m tall.

Where is it found?

Cecropia trees have been grown as ornamental plants. They have naturalised in northern NSW, south-east Queensland and northern Queensland. Cecropia trees have been found near Lismore, Burringbar, Murwillumbah on the North Coast and in Moree in the North West. Most of these were planted as ornamental trees. Many cecropia seedlings were found on the North Coast sites where there were both female and male trees present.

Cecropia is native to southern Mexico, Central America and the West Indies. It is a significant weed of roadsides and natural areas in tropical Africa, tropical Asia and on some Pacific islands.

What type of environment does it grow in?

Cecropia grows best in tropical climates, but will grow in subtropical and warm temperate areas. Trees prefer full sun and grow in open areas, on the edges of forests or where there are large gaps in the forest canopy.

Seedlings will grow prolifically in sunny areas but rarely grow and survive under dense shady canopies.

Maps and records

• Recorded presence of Cecropia during property inspections (Map: Biosecurity Information System - Weeds, 2017-2023)
  These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.
  
  

How does it spread?

By seed

Plants start producing seeds when they are 3-5 years old and each tree can produce about 20,000 viable seeds per year. It is necessary to have a male tree in close proximity to female trees to produce viable seeds/ Seeds are viable in the soil for up to 6 months. Cecropia species can be long lived.

Birds and fruit bats eat the fruit and can spread the seed kilometres from the parent tree. Flowing water and movement of soil can also spread the seeds.

By plant parts

Stems can root at the nodes. Dumped garden waste may have caused some spread.

What type of environment does it grow in?

Cecropia prefer tropical climates, but will grow in subtropical and warm temperate areas.

They are best adapted to disturbed sites with plenty of light and moisture, and where the soil is fertile.

Seeds rarely germinate under dense canopies, but can be prolific in canopy gaps. Plant growth is poor in shaded areas and plants will not persist in the shade.

They are potential weeds of closed-forest gaps and margins, riparian areas, gullies, roadsides, abandoned farmland, wasteland and other disturbed areas.

References

Australia’s Virtual Herbarium: Broussonetia papyrifera. http://avh.ala.org.au/occurrences/search?taxa=Cecropia#map 

Brisbane City Council Weed Identification Tool: Trumpet Tree (Cecropia palmate/peltata). http://weeds.brisbane.qld.gov.au/weeds/trumpet-tree-cecropia-palmata-peltata 

CABI (2007) Invasive species compendium: Cecropia peltata (trumpet tree. Downloaded 18 October 2022 from https://www.cabi.org/isc/datasheet/11955

Csurhes, S. (208). Pest plant risk assessment Cecropia (Cecropia spp.). Queensland Department of Primary Industries. http://www.daff.qld.gov.au/__data/assets/pdf_file/0011/68969/IPA-Cecropia-Risk-Assessment.pdf 

Far North Coast Weeds Weed Information: Cecropia peltata. http://fncw.nsw.gov.au/weed-information/new-and-emerging-weeds-index/cecropia-peltata/

More information

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Control

Successful weed control requires follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.

To manage cecropia:

• report suspected plants to the local council weeds officer for help identifying the trees and for advice about removal and control
• remove mature trees to stop seed production
• once mature trees have been removed, check for and control seedlings in these areas around female trees) each month for 6 months.

Physical removal

Hand pull or dig out small seedlings.

Chemical control

Spot spray

Small seedlings can be spot sprayed. Ensure that all of the foliage is covered with the herbicide mix.

Stem injection

Drill downwards holes into the trunk all the way around the tree. Alternatively make cuts with a saw or axe all the way around the trunk. Fill each hole or cut with herbicide within 15 seconds. 

Cut stump method

Cut the trunks, and apply herbicide to the stump within 15 seconds of cutting.

Disposal

Stems will grow if left in contact with the soil. The stems and trunks can be chipped. Contact your local council for further advice on how to dispose of this weed.

Herbicide options

See Using herbicides for more information.

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 1 part glyphosate to 1.5 parts water
Comments: Cut stump application.
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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Picloram 44.7 g/L + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump application. Apply a 3-5 mm layer of gel for stems less than 20 mm. Apply a 5 mm layer on stems above 20 mm.
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Biosecurity duty

The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.

Area	Duty
All of NSW	General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable.
North Coast	Regional Recommended Measure* (for Regional Priority - Eradication) Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found.
	*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here

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Reviewed 2023