Quick Facts

Quick facts

• Madras Thorn (Pithecellobium dulce) is not yet naturalised in Australia but has been cultivated in gardens in northern Queensland.
• It has the potential to invade pastures and out-compete desirable species, including native vegetation.
• It forms impenetrable thickets.
• Its sap can cause eye irritation and skin welts.
• It is best controlled by chemical means.

What Does It Look Like?

What is it?

Madras Thorn (Pithecellobium dulce) is a small to medium-sized thorny tree usually growing up to 10 m tall, but occasionally reaching up to 20 m in height, and forming dense thickets. The trunk is spiny and the bark is greyish, becoming rough and furrowed with age. Each leaf consists of two pairs of relatively large leaflets, 20-40 mm long, asymmetric, and oblong or egg-shaped in outline. Each leaf stalk bears a pair of small spines, 2-15 mm long, at the base.

The fragrant flowers are greenish-white, turning yellowish with age, and are borne in dense globular clusters about 10 mm across.

The pods (fruit) are irregularly swollen and strongly twisted or coiled. The pods are 10-13 cm long when uncoiled and 10-15 mm across, and have a pinkish hue. These pods contain a white pulp and 5-12 reddish-brown to black seeds. The shiny seeds are about 10 mm long, and are attached to the pod by a pulpy reddish thread about 2 cm long (Navie 2004).

For further information and assistance with identification of Madras Thorn, contact the herbarium in your state or territory.

Flower colour

Yellow, White, Green

Growth form (weed type/habit)

Tree

Where it currently grows? Preferred habitat

Madras Thorn is drought tolerant. It can grow on poor soils in dry climates and along coastlines, including areas where its roots are in brackish or salt water (DPI 2007).

Madras Thorn is a potential weed of pastures, open woodlands, rangelands, roadsides, disturbed sites and waste areas in drier tropical and subtropical environments (Navie 2004).

Are there similar species?

Madras Thorn is relatively similar to Leucaena (Leucaena leucocephala) and the native Bean Tree (Bauhinia gilva) [as Lysiphyllum gilvum]. Leucaena is a thornless plant with compound leaves that have numerous pairs of small leaflets 7-15 mm long. Bean Tree is a thornless plant with compound leaves that consist of a single pair of relatively large leaflets, 20-40 mm long. Its flowers are white to reddish, 20-30 mm across, and have five petals 8-12 mm long (Navie 2004).

Why Is It A Weed?

What are its impacts?

Agriculture: Madras Thorn is a destructive pest that forms dense impenetrable thickets. It has the potential to invade pastures and out-competes desirable species including native vegetation.

Native ecosystems: It could spread quickly across vast tracts of tropical and subtropical areas to become a costly weed of agriculture and the environment (DPI 2007).

Human impacts: Its sap can cause eye irritation and skin welts (PIER 2008).

How does it spread?

Madras Thorn resprouts rapidly from basal or aerial shoots when damaged, but the major means of reproduction is through seeds. These seeds are readily eaten and dispersed by birds and other animals (Navie 2004).

What is its history in Australia?

Madras Thorn has not yet become naturalised on the Australian mainland. However, it has been reported from Christmas Island in the Indian Ocean (Navie 2004).

A single, cultivated tree was found during a plant health survey in north-western Cape York Peninsula in 2002-2003. The property owners had obtained the tree as a sapling 16 years earlier from an amateur nursery near Cairns. Since then, they had attempted to cut the tree down, but it had regrown. No seedlings were evident in the vicinity of the tree. It is possible that other trees originating from the same nursery are present in north Queensland (NAQS 2007).

How To Manage It?

Best practice management

Prevention: Madras thorn is rare in Queensland, possibly restricted to gardens. An opportunity exists to prevent it becoming a serious problem here. To achieve this, madras thorn must not be sold or grown as a garden ornamental anywhere in the state (QLD DAF 2020).

Non-Chemical control: Mechanical control: Mechanical removal is difficult because Madras Thorn resprouts readily, but it can be controlled by chemical means. Larger trees can be cut and the stumps treated with herbicide to prevent resprouting.

Chemical control: Foliar and basal herbicide treatment may be effective on smaller trees and seedlings (PIER 2008).

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

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Under favourable conditions, Madras Thorn can reach a height of 10 m in five to six years. Its leaves are deciduous, but new leaf growth coincides with the loss of old leaves, giving the tree an evergreen appearance. Flowering begins in three to four years and is seasonal (April in Hawaii). Seeds do not require any treatment to germinate and, being legumes, the seeds are likely to have prolonged dormancy in the soil (Brewbaker 1992; Csurhes & Edwards 1998; PIER 2008).

Where Is It Found?

Which states and territories is it found?

Found on Christmas Island. Not naturalised in any Australia state or territory but garden plants occur in NT and QLD.

What areas within states and territories is it found?

Madras Thorn has been reported from Christmas Island in the Indian Ocean and a single cultivated tree is known from Cape York Peninsula. It may occur elsewhere in Queensland, but it is probably restricted to gardens (Navie 2004; DPI 2007; NAQS 2007).

Where does it originate?

Madras Thorn is native to North, central and South America, from California and Mexico through to Colombia and Venezuela (Navie 2004).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

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

Pithecellobium dulce

Other scientific names (synonyms)?

• Mimosa dulcis Roxb.
• Inga dulcis (Roxb.) Willd.
• Inga javana DC.

Does it have other known common name(s)?

Manila Tamarind, Monkey Pod, Victorian Box, Victorian Laurel, Bread-and-cheese, Blackbeard, Sweet Inga, Sweet and Thorny, Camachile Tree, Opiuma, Honey Tamarind