Quick Facts

Quick facts

• Originally from southern Africa, southern Europe, and western Asia, Spanish Broom (Spartium junceu), is a shrub to 3-5 tall with rush-like stems, single leaves that are soon lost, and showy bright yellow pea-like flowers, and typical broom-like flat pods.
• Spanish Broom is sparingly naturalised in South Australia, Queensland, New South Wales, the Australian Capital Territory, and Victoria.
• There is the potential for Spanish Broom, like other introduced brooms, to become a serious weed.
• Spanish Broom can be confused with other introduced Brooms, notably English Broom, but it may be differentiated as Spanish Broom has branchlets that are circular, rather than five-angled, in cross-section and undivided leaves, not compound leaves with 3 leaflets.
• Control is possible using manual, chemical and fire methods, either singly or in combination (integrated management).

What Does It Look Like?

What is it?

Spanish Broom (Spartium junceum) is an upright, perennial (long lived), deciduous shrub that grows to 3 metres tall occasionally to 5 metres tall (especially in cultivation). Its branches are rush-like i.e. long, slender and upright, cylindrical in cross-section, finely ribbed, pith filled, grey green to dark green, spineless and mostly leafless. The single entire leaves (not divided in to leaflets, having a smooth margin that is not lobed, divided or toothed), which are shed after a few months, have stalks 1–4 mm long, are  alternately arranged. The leaves are oval to oblong in shape, with parallel sides and smooth margins (edges), are 2–4 times long as broad being 10–40 mm long and 2–10 mm wide. The upper surface is hairless, and the lower surface is hairy when young.

The inflorescence (flower stem / structure) forms at the tip of the branches (branchlets) and consists of 5–15 sometimes to 30 sweetly fragrant, yellow, typical pea-like flowers, 20-28 mm long, borne singly, widely spaced along the branchlet in the forks of the leaves or where the leaves were, on stalks 2–5 mm long. The petals are asymmetrical, the calyx 5–7.5 mm long, .

The fruits are typical broom-like pods, 50–100 mm long, up to 6 mm wide, about 6-15 times longer than broad with parallel sides, and more or less flattened (not rounded), pods with silky hairy, but later becoming hairless, splitting open by two valves at maturity. There are 10–20 smooth, brown to yellowish-brown shiny seeds per pod (Heywood 1968; Webb 1988; Zouhar 2005). Flowers in late spring to mid-summer from October to December.

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

Flower colour

Yellow

Growth form (weed type/habit)

Shrub

Where it currently grows? Preferred habitat

Spanish Broom is usually found close to towns and urban areas, and in agricultural areas near old farmhouses. It is typically a weed of disturbed sites such as roadsides and railway lines, as well as disturbed urban bushland, streams, and roadside drains (AVH 2020).

It has been collected from various soil types: in Queensland it has been recorded as growing on red soil at Toowoomba in south-eastern Queensland, growing on sandy soil in the Darling Downs and growing on black clay at Inverell in New South Wales. It has been collected from dry, low rainfall regions such as from roadside mallee scrub on the Eyre Peninsula in South Australia, to cooler, more elevated and mesic (moist) sites at Inverell, where it has naturalised along the MacIntyre River (AVH 2020).

Are there similar species?

Spanish Broom may be confused with a number of other introduced Broom species.

English (or Scotch) Broom (Cytisus scoparius) is perhaps the species most likely to cause confusion in the identification process. However, the branchlets of English Broom are characteristically prominently five-angled in cross-section where the branchlets of Spanish Broom are rounded in cross-section, with many fine lengthwise ribs. The leaves of English Broom are composed of three leaflets, while those of Spanish Broom are not divided into leaflets (Heywood 1968; Webb 1988).

There are a number of native shrubs in the pea family which may potentially be confused with Spanish Broom. Dogwood (Jacksonia scoparia) has furrowed black bark, strongly angled or winged branchlets, and is often weeping in habit. Its flowers are smaller than Spanish Broom's and are cream or orange-yellow, and the pods are tiny (Wiecek & Williams 2002).

The Native Broom (Viminaria juncea) is an upright shrub with pendulous branches, with the young leaves having 1-3 leaflets. The corolla (collective term for petals) is 7-10 mm long, yellow to orange and often has red blotches. The pods are small, 4-5 mm long. It grows in swampy habitats near the coast (Wiecek 2002).

Why Is It A Weed?

What are its impacts?

Spanish Broom (Spartium junceum) is commonly grown as a garden ornamental, particularly in the cooler parts of Australia. It has escaped cultivation and is regarded as a minor environmental weed. Spanish Broom is able to fix nitrogen and can increase the nitrogen content of the soil at the sites where it invades and facilitate the invasion of other weeds (Zouhar 2005; Southern Tablelands and South Coast Noxious Plants Committee undated). Broom species primarily threaten natural habitats such as conservation areas at present, although they may also compete with favourable species in pastures. Spanish broom can dominate disturbed areas where it can out-compete native plants and alter soil nutrients (DPI NSW 2019) 

Agriculture: To date, limited impact in primary production areas, with potential to invade poorly managed pastures and hobby farms if left unchecked.

Native ecosystems: Native flora and fauna are threatened when native plants are out-competed and natural habitat is replaced by infestations of Broom species. Broom species may also harbour rabbits. These weed species are able to invade seemingly undisturbed bushland and therefore represent a significant threat to ecological values (Regional Weeds Advisory Committee 2002; Southern Tablelands and South Coast Noxious Plants Committee undated). In Victoria, Spanish Broom invades lowland grassland, grassy woodland and rock outcrop vegetation, and it is listed as being a 'potential threat to one or more vegetation formations' (Carr et al. 1992). Although currently Spanish Broom is relatively sparingly naturalised in Australia, there is potential for the species to become a more serious weed in the future, as it has in California (Zouhar 2005).

Urban areas: Occasionally persistent and  spreads in abandoned gardens in to roadside, and little managed urban areas. The seeds and leaves of Spanish Broom, if eaten in large quantities, are very poisonous, especially to children. They contain the toxin quinolizidine alkaloid cytosine and sparteine (Shepherd 2004). Spanish broom is toxic to humans a but is not considered life-threatening. Symptoms when ingested include, causing nausea, diarrhea, convulsions and respiratory distress. 

What to do if poisoning occurs:

• If the patient is unconscious, unresponsive or having difficulty breathing dial 000 or get to the emergency section of a hospital immediately.
• If the patient is conscious and responsive call the Poisons Information Centre on 13 11 26 or your doctor.
• If going to a hospital take a piece of the plant for identification.

How does it spread?

Spanish Broom is dispersed solely by seeds, which are ejected explosively as the pods dry out on warm, sunny days in summer. Data from the United States of America indicates that most of the seeds fall within a few metres of the parent plant, and are subsequently dispersed by erosion, rain wash, and possibly ants (Nilsen 2000).

As with English Broom (Cytisus scoparius), it is probable that the seeds could be dispersed by water when the plants are growing near streams, as well as by mud on machinery such as road graders and slashers, vehicles and footwear (Muyt 2001; Parsons & Cuthbertson 2001). It is also likely that the seeds could be spread by the hooves of livestock such as sheep, cattle and horses that have been feeding in infested sites as well as in wool (Southern Tablelands and South Coast Noxious Plants Committee, undated). The dumping of garden waste containing the seeds of Spanish Broom or contaminated soil are other possible means of dispersal (Muyt, 2001)

What is its history in Australia?

Spanish Broom was introduced to Australia as a garden ornamental plant. The earliest listing in a Victorian nursery catalogue was in 1857 (Brookes & Barley 1992). It is not yet widely naturalised. The earliest recorded naturalisation in South Australia is from a specimen collected in 1983 (AVH 2020). In Queensland, the first recorded naturalisation is from Bardon, in Brisbane, from a specimen collected in 1999 (Queensland Herbarium 2008). The first and only recorded naturalisation in New South Wales is from Inverell, collected in 2004 (National Herbarium of New South Wales 2008). The National Herbarium of Victoria holds only two Victorian specimens collected from naturalised populations (National Herbarium of Victoria 2008).

How To Manage It?

Best practice management

Allegedly sterile hybrid forms of Spanish Broom (Spartium junceum) are still sold in nurseries. These have been observed to produce seed and revert to the wild type, and should not be planted (Southern Tablelands and South Coast Noxious Plants Committee undated).  The same or similar control methods can be applied to Spanish broom (Spartium junceum), that are applied to other WoNS brooms including Cytisus scoparius, which is a major weed in southern Australia (Office of Environment and Heritage. 2014). Although not as invasive as other Broom species, follow-up monitoring and removal of seedling is required when undertaking control of Spanish Broom. Seedlings can be sprayed or hand pulled. Prolific seed production and long viability results in a large soil seed bank which will continue to germinate for many years after mature plants are removed.

Chemical control: With large infestations, the most effective control will probably be achieved by applying herbicides, as part of an integrated management plan, to gain initial reduction of the weeds as a first step. It is best to apply the herbicides when the plants are in full leaf (Zouhar 2005). For control of Spanish Broom, methods applied to Cytisus scoparius, should be effective, but follow-up is required until the seedbank has been depleted. Some useful herbicide control methods for the WoNS brooms can be seen in Office of Environment and Heritage (2014) and DPI NSW (2019). Please follow your States or Territories guidelines, contacting relevant authorities if you are unclear, and follow herbicide label information before proceeding.  Herbicide application methods for other weedy brooms include:

Foliar spraying: For the application of herbicide solution to weed foliage in the form of a spray, a common method used for woody plants. Foliar spraying can be used to treat plants of all ages but can be less effective on older plants.

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. This is useful for large plants, that are cut and painted with herbicide to prevent re-sprouting.

Basal barking: 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.

Stem injection (drill-and-fill): Stem injection delivers herbicide directly to the sapwood but is rarely used on brooms, but when used, it is for plants with stems over 50 mm in circumference.

Scrape-and-paint: This method involves scraping away a small section of the bark and applying herbicide directly onto the sapwood. It is an effective but rarely used technique normally used on larger plants.

Splatter or gas gun:  splatter guns were developed over thirty five years ago for sheep drenching and has been adapted for weed spraying using chemicals.

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

Non-chemical control: Physical control: Physical removal is an option for isolated plants, especially if they have not seeded; although seedlings are hard to hand pull, tools can be used making removal easier. However, it will be necessary to monitor the treated area for many years and destroy any new plants that germinate from the soil seed bank.

Mechanical control: Bulldozing infestations into heaps and burning the resulting weed mounds has been a common method used to control Broom but it only provides a temporary solution. Bulldozing causes massive soil disturbance, and physical movement of plants not only burying seeds but also spreading them beyond the original infestation.

Cultural: Infestations of young plants can also be grazed to prevent the plants maturing, flowering and setting seed. However, grazing needs to be continued until the soil stored seed bank is exhausted (Hoshovsky 2001).

Fire: Fire effectively kills plants and can help to break seed dormancy. Fire may be helpful in encouraging most seed to germinate and produce seedlings that can then be sprayed. However, fire without follow up treatment is only likely to make the situation worse (Southern Tablelands and South Coast Noxious Plants Committee undated).  Experience using fire to control other species of broom indicates that it kills a large proportion of seeds but lightly scorched plants may re-sprout.  Follow-up chemical treatment after fire will probably be needed until the seed-bank is depleted.

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

In Australia, flowering material of Spanish Broom has been collected between September and January, with a single flowering specimen collected in April from South Australia (eflora of South Australia 2008). The flowering period in New Zealand is between December and May (Webb 1988). As with the related English Broom (Cytisus scoparius), the information available from herbarium specimens indicates that pods mature during summer, and perhaps autumn (National Herbarium of Victoria 2008).

In the United States of America, plants of Spanish Broom usually do not produce seeds until at least two or three years old, and a single plant can produce 7 000 to 10 000 seeds in one season. The seeds remain viable for at least five years, and autumn and spring rains initiate seed germination (Nilsen 2000; Zouhar 2005). They germinate readily without any pre-treatment (Hellmers & Ashby 1958).

Where Is It Found?

Which states and territories is it found?

ACT, NSW, QLD, SA, TAS, VIC

What areas within states and territories is it found?

In South Australia, it occurs on the Eyre Peninsula, the Yorke Peninsula and in the Southern Lofty, and South-East regions. In Queensland, it has been collected from the areas of Brisbane and Toowoomba. In the Australian Capital Territory it is found in Canberra, and in New South Wales it appears to be naturalised at Inverell. In Victoria, it is has been collected near Colac, and at Yarra Bend in Melbourne, in Tasmania most collections have been made around the Hobart area. (AVH 2020).

Where does it originate?

Spanish Broom is native to northern Africa, western Asia and southern Europe, and is naturalised elsewhere (GRIN 2008).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

ACT

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

Spartium junceum

Other scientific names (synonyms)?

Does it have other known common name(s)?

Weaver's Broom