Quick Facts

Quick facts

• Originally from North Africa, Arabian peninsula and India, Athel Pine (Tamarix aphylla), a Weed of National Significance, is a fast growing tree with serious impacts along waterways in arid and semi arid Australia.
• Readily established on saline and alkaline soils, spread by seed, and broken stem material that is moved by flood water. All new plants become reproductive at three years of age.
•  established plants also spread vegatatively as roots develop and plant sucker from fallen and buried or limbs and stems.
• The movement of soil by earth-moving machinery containing fresh seed and root fragments is another means of spread. Good weed hygiene avoids further spread.
• Control requires a strategic program integrating a range of techniques including manual removal and chemical applications.
• It is a threat to the pastoral and tourism industry and the riparian biodiversity of central Australia.

What Does It Look Like?

What is it?

Athel Pine (Tamarix aphylla) is an evergreen tree, single stemmed or multi-stemmed, to 15 m tall,  Bark is rough grey-brown, with older bark darker grey or greyish brown, rough and deeply furrowed. Bark on new younger stems is reddish-brown to grey-green in colour, smooth and appear jointed. Leaves are reduced to tiny scales, 1-2 mm long and are alternately arranged along the fine branchlets (which are often mistaken for cylindrical leaves giving branches with leaves a cylindrical appearance).

Flowers are pale-pink to white, small in elongated clusters, 30-60 mm long and 4-5 mm wide near the tips of the branches. Flowers have 5 small petals about 1.5-2 mm long, stalkless.

Fruits are bell shaped capsules, 2-3 mm long and contain numerous seeds that are topped with a tuft of tiny hairs (Fuller 1998; CRC 2003). Seeds are viable but short lived.

Recognition: This species can normally be recognised by the combination of the following characters; Erect tree or multi-stemmed tree; new fresh green leaf growth cylindrical with green scales; light pink to white flowers at the end of branches 30-60 mm long; normally growing in arid to semi-arid areas near or in drainage lines, creeks or rivers. Can be difficult to distinguish from other Tamarix species.

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

Flower colour

White or pale pink.

Growth form (weed type/habit)

Tree

Where it currently grows? Preferred habitat

Athel Pine (Tamarix aphylla) grows in semi-arid, arid, sub-tropical and warmer temperate regions and is particularly common along inland waterways, as well as near towns, communities, homesteads, stockyards and bores. It is also a weed of open woodlands, grasslands, pastures and roadsides (Navie 2004). It is tolerant of saline and alkaline soils (CRC 2003). Maps of Athel Pine's current and potential distribution can be found at https://www.weeds.org.au/WoNS/athelpine/ 

Are there similar species?

Athel Pine (Tamarix aphylla) is very similar to other Tamarix species. Tamarisk (Tamarix ramosissima) and Small Flower Tamarisk (Tamarix parviflora). Athel Pine is a medium sized evergreen tree up to 15 m that has tiny overlapping leaves that sheath the stem.

Tamarix ramosissima and Tamarix parviflora are large multi-trunked shrubs or small deciduous tree less than 5 m that have tiny stalkless leaves that differ significantly to Athel Pine (Navie 2004).

Athel Pine has a similar appearance to Native She-oaks, Casuarina spp., and Allocasuarina spp. Athel Pine can be distinguished from these native plants by its fruit and close inspection of the scale leaves. Native She-oaks have scale leaves arranged in whorls around the branchlets. The scale leaves of Athel Pine are alternately arranged along the branchlets. Native She-oaks produce hard woody fruit that resemble small pine cones (CRC 2003; Navie 2004).

Why Is It A Weed?

What are its impacts?

Athel Pine (Tamarix aphylla) is a Weed of National Significance. It is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts. It increases surface soil salinity changing ecosystems, shades and competes with desirable species.

Agriculture: Athel Pine impacts the pastoral industry by increasing the difficulty of mustering, and decreasing pasture production. It contributes to the drying up of waterholes, thus reducing the number of watering points, increasing management pressures and reducing carrying capacity (ARMCANZ 2001).

Native ecosystems: Athel Pine displaces Eucalyptus species and other native vegetation, resulting in dominance of the ground vegetation by relatively few species of introduced or salt-tolerant plants, and a reduction in the number of birds and reptiles (Fuller 1998) and invertebrates (Gouldthorpe 2008). The replacement of native vegetation with Athel Pine may also alter the fire regime as it does not burn well and hence suppresses the natural tendency of fire to provide a trigger for regeneration of native species. Athel Pine excretes salt through its leaves which leads to higher salinity levels in the dense compacted litter. It does not form nesting hollows so nesting sites are lost when Athel Pine displaces native vegetation (ARMCANZ 2001).

Athel Pine is drought resistant and varies its water use dependent on availability. It is responsible for lowering water tables, and thus draining waterholes and depriving native flora of water (Fuller 1998). Dense Athel Pine infestations increases sedimentation rates by trapping and stabilising sediment during river flows. This can cause increased overland flooding and erosion (ARMCANZ 2001).

Athel Pine also impacts the tourist industry by reducing the aesthetic value of rivers and creeks in Central Australia (ARMCANZ 2001).

Urban areas: Accelerates rusting of roofs, gutters, fences water mains, building overhung by Athel Pine.

How does it spread?

Athel Pine (Tamarix aphylla) reproduces by seeds that are dispersed by wind, flood waters and animals. The viability of seed is short, usually only a few weeks.

Athel Pine also spreads via suckering and the rooting of buried or submerged stem segments that have broken from the tree and been carried significant distances by flood waters (Navie 2004).

What is its history in Australia?

Athel Pine (Tamarix aphylla) was introduced to Australia in the 1930s and 1940s as a useful tree in arid and semi-arid regions (Broken Hill and Whyalla). Plantings in other states followed in the 1940s and 1950s. It is classified as a sleeper weed because it was present in Australia for some time before it became weedy (CRC 2003). Extensive infestations occurred along the Finke River during the 1970s and 1980s as a result of extensive floods (ARMCANZ 2001).

How To Manage It?

Best practice management

Athel Pine (Tamarix aphylla) can be controlled by chemical and physical methods. However, follow-up is always required to control re-growth from root-stocks. Germination by seeds may also occur. Preventing spread is the most cost effective form of weed control. Cleaning down machinery is useful as soil on machines  may contain seeds or root fragments that can re-sprout and grow in new areas. 

Chemical control: Various herbicide are effective and available for uses Herbicide application methods are via

Stem injection (drill-and-fill): Herbicide can be injected into the bark of larger stems (Australian Weeds Committee 2011). Stem injection delivers herbicide directly to the sapwood. Stem injection should be no more than 100 mm apart as Athel Pine does not translocate herbicide laterally.

Cut-and-swab method (Cut stump treatment): is when each stem is cut off at ground level and immediately applying herbicide to the cut surface killing the plant to prevent regeneration from the rootstock. Cut stump application is suitable for large trees, but care must be taken to ensure that wounds are treated immediately and fallen trees are not left in moist soil where they may again take root.

Basal barking: Herbicide can be applied to the bark of smaller stems. This method involves applying herbicide mixed with an adjuant to the lower trunk or stem of woody plants up to around 50 mm in diameter to a height of 30–40 cm above ground level. Juvenile trees can be controlled by basal bark application, but full coverage is essential for this method and difficult if surface sand is present. Seedlings and juvenile trees are effectively controlled by foliar application (ARMCANZ 2001) making sure that the plant gets a complete coverage of herbicide.

Foliar spraying: Foliar herbicide spraying is the application of herbicide solution to weed foliage in the form of a spray, and normally is used for extensive seedling growth and limited regrowth from cleared trees and shrubs.

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

NOTE: Training is normally a requirement in most States and Territories for all or some of the methods.

Non-chemical control: Non chemical control methods are usually followed up with chemical (herbicide) applications. 

Physical control: Hand pulling can be useful for small infestations of seedling under 60 cm or where weed control requires sensitive avoiding native vegetation.

Mechanical control:  Machine control can be by bulldozing to remove individual trees or large populations. Care should be taken to remove all the root system and ensure that sand is not covering uprooted and felled stems as they may re-shoot. Chainsaws can be used to remove individual trees but herbicide must be applied at the same time (ARMCANZ 2001) with care being taken due to brittle branches.

Cultivation: or blade ploughing or the use of a cutter-bar is suited to large infestation of seedlings in wide, open, sandy creeks and rivers.

Flooding: Can be used in areas regulated by waterways to kill plants by submerging and drowning, but thus method is slow acting and non-selective.

Biological control: Although biological control is being investigated by the United States of America Department of Agriculture for other Tamarix species (ARMCANZ 2001) biological control is currently not available in Australia. The athel pine has not been endorsed as a candidate species for biocontrol research by the Environment and Invasives Committee (Hervey et al 2023).  

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Seeds of Athel Pine (Tamarix aphylla) germinate for most of the year provided moisture is available but main germination period is autumn. Seedlings can reach a height of 60 to 100 cm in the first year. Subsequent growth is rapid, with trees reaching heights of 2 to 5 m under favourable conditions. First flowers appear in about the third year and every summer thereafter (ARMCANZ 2001).

Where Is It Found?

Which states and territories is it found?

NSW, NT QLD, SA, VIC, WA

What areas within states and territories is it found?

Athel Pine (Tamarix aphylla) is widely distributed in the inland arid areas of Australia. It has naturalised in the Northern Territory, South Australia, Queensland and Western Australia. It has also been recorded in Victoria (Navie 2004). The worst infestations of Athel Pine occur along the lower 600km of the Finke River in central Australia (CRC 2003) and along waterways and by water bodies including; Yandama, Tilcha, Coonee, and Boolkaree Creeks that feed into Lake Callabonna and at Lake Starvation in South Australia (Greenfield 2007).

Where does it originate?

Athel Pine (Tamarix aphylla) is native to northern Africa, the Arabian peninsula, Iran and India (Fuller 1998).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

YES

Where is it a declared weed?

Declared in all Australian states and territories.

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

Tamarix aphylla

Other scientific names (synonyms)?

Thuja aphylla L.

Does it have other known common name(s)?

Athel Tree, Tamarisk, Athel Tamarisk, Athel Tamarix, Desert Tamarisk, Flowering Cypress, Salt Cedar.