Description
Cutch Tree is a small tree, growing 3-15 m high with a taproot branching to 2 m depth. The stem is dark brown to black, with rough bark which peels off in long strips in mature trees; young trees have corky bark. The compound leaves are 100-200 mm long and comprise 8 - 30 pairs of primary leaflets each made up of numerous, oblong pairs of secondary leaflets 2-6 mm long. Glands occur on the stem below the first pair of leaves, and between the uppermost six pairs of leaflets. Pairs of stout thorns up to 10 mm long are found at the base of each leaf. The flowers are white or pale yellow, in a cylindrical flower spike 35-75 mm long. The seed pods are 50-125 mm long and contain between four and seven seeds, which are dark brown, flat and 5-8 mm in diameter.
For further information and assistance with identification of Cutch Tree contact the herbarium in your state or territory.
Distribution:
To date, Cutch Tree has only been found in Darwin in the Northern Territory.
Habit:
Tree
Key points:
- Known infestations of Cutch Tree (Acacia catechu) in Darwin are currently under active management, with eradication as the target.
- Preventing its spread and further introduction will protect the savannas and grasslands of tropical Australia.
- Small infestations of Cutch Tree can be effectively eradicated if follow-up control is conducted.
- Contact your state or territory weed management agency or local council if you find Cutch Tree. Do not attempt control on your own.
How it spreads:
Cutch Tree reproduces by seed. Mature trees produce large numbers of seeds, which can be transported from the parent tree by cattle. The seeds remain viable even after passing through the digestive tract, and can be spread large distances in this way. Seeds can also be spread by the actions of water and people, or in mud sticking to animals or machinery. Although the exact length of time of seed viability is not known, based on related woody weed species it is likely that some seeds remain viable for about 20 years in suitable conditions. Cutch Tree will also resprout from the base if the main stem is removed and the cut stump is not treated with herbicide. The regrowth is frequently very dense and composed of numerous stems.
Where it grows:
Cutch Tree prefers subtropical or tropical open woodlands and grasslands. It grows well on most soils, but well-drained, shallow to medium-depth sandy soils suit it best. In its native range Cutch Tree has the tendency to invade degraded areas, e.g. overgrazed grasslands. Regular burning is also conducive to its spread.
Flower colour:
White, Yellow
Distribution map:
Impacts:
Cutch Tree is on the Alert List for Environmental Weeds, a list of 28 non-native plants that threaten biodiversity and cause other environmental damage. Although only in the early stages of establishment, these weeds have the potential to seriously degrade Australia’s ecosystems.
Cutch Tree causes economic damage by forming dense impenetrable stands. It can potentially reduce primary production by displacing and/or shading pastures. The sharp thorns on Cutch Tree branches can impede the movement and mustering of stock.
Origin:
Cutch Tree is native to the Indian sub-continent, including Assam and Myanmar (Burma), as far as the lower Himalayan ranges and Afghanistan.
History:
In the 1887 Government Resident’s Report, Cutch Tree was included in a list of useful plants grown in the Darwin Botanic Gardens. In the early 1980s concern was expressed about its weed potential in the Northern Territory. It is not known how Cutch Tree escaped the Darwin Botanic Gardens to reach Darwin High School at Bullocky Point, about half a kilometre away, although transport by people, animals or machinery appears likely. Cutch Tree has the potential to be a very serious woody weed of the tropical savannas and grasslands of Australia. The Bullocky Point infestation has been eradicated but the plant persists in the Darwin Botanic Gardens.
