Quick Facts

Quick facts

What Does It Look Like?

What is it?

African Boxthorn (Lycium ferocissimum) is a dense spiny woody shrub up to 4–5 m high and 3–5 m wide, without any hairs on any of the parts. Stems are smooth and silver-grey when young, becoming brown and fissured as they mature. Rigid branches and stems end in sturdy stout spines and thorns that are 20-150 mm long. Leaves are small 10–40 mm long by 4–11 mm wide, semi-fleshy to fleshy and often clustered in groups, thinly obovate (egg-shaped with the widest part nearer the tip of the leaf), with the base of the leaf attenuate (narrowing gradually), with a short petiole (leaf stalk), and the leaf tip rounded to blunt, leaf margins entire (smooth not toothed or lobed).

The small tubular flowers, about 10 mm in diameter and 10–12 mm long with five lobes (petals), are produced individually or in pairs below where the leaf originates on the stem. The pedicels (flower stalks) are 5–16 m long.  Flowers are pale lilac or white, often blotched lilac towards base, deeper purple inside the flower tube.

The fruit is green at first, ripening to a red or orange red shiny berry on a short down-turned stalk. It is round, 5-12 mm diameter and slightly wider at the end away from the green calyx which envelops the base of the fruit. There are 20 to 70 seeds per fruit (Noble and Rose 2013). Seeds are oval or irregular in outline shape, flattened, 2.5 by 1.5 mm, light brown to yellow (Purdie et al. 1982; Navie 2004).

Recognition: This species can normally be recognised by the combination of the following characters; A spiny dense hairless shrub with small obovate leaves; tubular small flowers to 10-12 mm long with 5 petals and exerted stamens with purple blotches  inside; red-orange to red fruits 5-12 mm diameter.

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

Flower colour

White and Purple

Growth form (weed type/habit)

Shrub

Where it currently grows? Preferred habitat

African Boxthorn is able to grows in a huge variety of climates, habitats, soil types, in a range of positions, from partial shade to full sun, found in both agricultural and native vegetation. It grows on waste-land, creek-beds, along waterways, fence-lines, roadsides, sandy and coastal areas, in woodlands, in rangelands and uncultivated pastures.

Are there similar species?

A native species, Lycium australe, is found in subsaline soils in semiarid areas of Western Australia, South Australia, New South Wales and Victoria. The most obvious differences are that it has smaller berries (2-5 mm diameter) than African Boxthorn and the stamens are of a similar length to the flower whereas those of African Boxthorn protrude beyond the petals (Barker 2007, pers. comm.).

There are two other introduced species of Lycium naturalised in Australia.

Lycium barbarum is presently of interest because it is the Goji berry of the health food market. It is found in south-eastern Australia. Unlike African Boxthorn its branches are weak and arching.

Lycium afrum is recorded from Victoria and Tasmania and has deep maroon flowers and purplish or black berries (Barker 2007, pers. comm.; CRC 2007).

African boxthorn can also look superficially similar to the native shrub Nitraria billardierei  that African Boxthorn is replacing in some sandy and coastal, semi-arid and arid areas across central, western and some southern areas of Australia.

Why Is It A Weed?

What are its impacts?

African Boxthorn is a Weed of National Significance (WoNS). It is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts. All parts of African Boxthorn (fruit, leaves, stem and roots) are poisonous to people, livestock and other animal species, although the level of risk is believed to be low (Noble and Rose 2013).

Agriculture: African Boxthorn can spread quickly if left unchecked. Having established it can rapidly form impenetrable, spiny thickets reducing stock movement and also the land available for pasture. Since birds are often the dispersing agent, infestations are commonly found around the base of taller trees. The fruit of African Boxthorn is a breeding ground for insect pests such as fruit fly, dried fruit beetles and tomato fly (Land Protection 2006). The taproot of the weed must be removed for control purposes otherwise it may produce re-growth, or if it is killed, it may still remain a hazard to stock and tyres because of its hardness and persistence (Land Protection 2006). The plant becomes a nuisance along fences, creeks,  and around dams and leaking troughs where it blocks passage along roads and prevents stock access to watering points. Leaves may be toxic to poultry (Noble and Rose 2013). Impenetrable thickets are sometimes regarded as shelter for livestock (Barker 2007, pers. comm.).

Native ecosystems: African Boxthorn also impacts the natural environment, e.g. displacing native vegetation and degrading fauna habitat.  Dense infestations may provide a haven for feral animals such as rabbits, sparrows (Land Protection 2006) foxes, feral pigs (Sus scrofa) and starlings (Noble and Rose 2013). However, impenetrable thickets are often cited as havens for small native birds and animals. Where African Boxthorn infests coastal areas and offshore islands it can significantly alter and interfere with native fauna habitats and has becomes the only woody plant present, changing the vegetation structure (Noble and Rose 2013). On islands off South Australia and Western Australia, African Boxthorn displaces the native shrub Nitraria billardieri, which is used by seals (Arctocephalus spp.) to shelter their pups. African Boxthorn does not provide an equivalent nursery habitat, leaving pups more vulnerable to predation. On islands inhabited by Australian sea lions (Neophoca cinerea), such as East Beagle Island off the coast of Western Australia, African Boxthorn grows down to the beach and is known to impede the sea lions’ access to the island for pupping. It also impacts various sea birds and birds have become entangled in the woody spiny plant and died.

Urban areas: Invades areas on urban fringes and abandon land and can forms impenetrable stands for people.

How does it spread?

African Boxthorn reproduces mostly by seeds that are commonly dispersed when the fruit are eaten by birds and other animals (e.g. foxes). Seeds may also be spread by water, machinery and in dumped garden waste or contaminated soil. Suckers are also sometimes produced from root fragments; shoots are rarely produced from stem fragments (Navie 2004).

What is its history in Australia?

African Boxthorn was introduced as a hedge plant for boundary demarcation, or possibly even as a garden plant, in the 1800s. Its wide use for this purpose in rural areas resulted in its extensive occurrence and naturalisation (Haegi 1976).

How To Manage It?

Best practice management

African Boxthorn (Lycium ferocissimum) is a Weed of National Significance (WoNS) in Australia due to its invasiveness, impacts, potential for spread and effects on socio-economic and environmental values. Several chemical and mechanical control methods are effective for managing African Boxthorn.

Chemical control: Chemicals (herbicides) can be used to control African Boxthorn.

Foliar sprays: can be applied when the plants are actively growing in spring or after rain when the plant is actively growing with follow-up in autumn. As the plant has a remarkably resilient rootstock, and will readily shed its leaves when under stress, foliar spraying does not produce such reliable results as it does for some other weed species.

Basal bark treatment:  spraying around the base of stems for plant up to around 50 mm in diameter to a height of 30-40 cm above ground level.

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.

Root application: is when a residual herbicide can be applied to the soil between the base of the plant and the drip-line, usually when the soil is wet or rain is expected (Land Protection 2006), and is normally used where there are no native plants to be affected.

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au , DPI NSW (2019) and (Noble and Rose 2013).

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

Physical control:  Manual (hand) removal is only possible when plants are small seedlings. Some Mechanical (machine removal) control of African Boxthorn is possible but there is likely to be re-growth from soil seed stores or from the taproot, meaning that cultivation and/or herbicides may need to be the next step. Mechanical control of Boxthorn is best done when the plant is not carrying fruit or seed; otherwise, fresh seed is likely to be deposited into freshly disturbed soil. Suitable mechanical techniques for managing African Boxthorn include the following:

Winching – involves pulling or winching (for example with a tractor and chain) can be used to remove large plants in difficult-to-access or fragile areas (such as coastal dunes).

Pulling or plucking – involves grabbing and lifting the plants mechanically with a front-end loader, articulated loader or excavator and is useful for treating light to moderate infestations and minimises impacts on surrounding vegetation.

Dozing, stick raking and blade ploughing – are most suitable for moderate to heavy African Boxthorn infestations where the risk of damaging non-target vegetation on production lands is not a concern.

Cultivation – In areas that are to be used for pasture or crops, after physically removing the African Boxthorn, cultivation can be a useful technique. It will break up roots remaining in the soil and bring root fragments to the surface, where they will dry out and/or should be raked and burned. Follow-up vigorous native perennial pastures compete with African Boxthorn. Establish pastures as soon as possible after weed removal. Consult an agronomist for advice on pasture establishment and management for your location.

Machine-based cut stump – Another option is machine-based cut-stump control, which involves cutting the plant near its base then immediately applying herbicide.

Disposal:  With each of the above techniques, African Boxthorn bushes should be piled and burnt.

Follow-up: Return to the site and treat regrowth from the roots or plant base with herbicide, and hand pull, cut and paint, or spray seedlings. Follow-up will be required until there is no more regrowth or seed germination.

Biological control: CSIRO has undertaken research that focuses on identifying which of the many natural enemies that attack African boxthorn in the native range of South Africa are the most appropriate candidate biological control agents for this weed (CSIRO 2015-2020). This research on African boxthorn has been part of the projects ‘Biocontrol solutions for sustainable management of weed impacts to agricultural profitability’ (2016-2020) and ‘Underpinning agricultural productivity and biosecurity by weed biological control‘ (2019-2022), led by AgriFutures Australia (the trading name of the Rural Industries Research and Development Corporation (RIRDC)). These projects have been supported by funding from the Australian Government Department of Agriculture, Fisheries and Forestry as part of its Rural R&D for Profit programme rounds 2 and 4, respectively. Biosecurity South Australia (Primary Industries and Regions South Australia), the Shire of Ravensthorpe, Western Australia, and the New South Wales Government through its Environmental Trust are also acknowledged for their financial support (CSIRO 2015-2020).

More information can be found here https://research.csiro.au/african-boxthorn/ 

Does it have a biological control agent?

YES. Mass rearing, release and monitoring of the rust Puccinia rapipes which has been approved for release.

When does it grow? (lifecycle/growth calendar)

African Boxthorn seeds may germinate at any time of the year. Flowering generally occurs in spring and summer, but some flowers and fruits are generally apparent most times of the year, particularly if sufficient moisture is available. Plants are at least two years old when they first bear flowers (Haegi 1976; Land Protection 2006).

Where Is It Found?

Which states and territories is it found?

Found in all Australian states and territories.

What areas within states and territories is it found?

African Boxthorn is found across southern Australia in agricultural and pastoral areas and waste places around towns and cities. It seems tolerant of most soil types and also some salinity. It is especially abundant in areas of high rainfall. Where its distribution enters drier regions the plants are generally found close to permanent or seasonal water supplies (Haegi 1976). African Boxthorn is generally found in cool to warm temperate areas, subtropical, semi-arid and arid to sub-humid areas (Navie 2004), and is common in all but the northern tropical parts of Australia (Noble and Rose 2013).

Where does it originate?

African Boxthorn is native to the coastal region of South Africa (Haegi 1976).

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, except 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

Lycium ferocissimum

Other scientific names (synonyms)?

• Lycium macrocalyx Domin
• Lycium europaeum L. (misapplied by Bailey, F.M. 1901, The Queensland Flora. 4: 1094.)

Does it have other known common name(s)?

Boxthorn