Quick Facts

Quick facts

• Common Heliotrope (Heliotropium europaeum) is an annual herb that is native to Eurasia and northern Africa.
• It grows up to 40 cm high, with trumpet-shaped flowers that are white with a yellow throat.
• It is poisonous to livestock if consumed in large quantities.
• It is extremely drought hardy, and is a common weed of the dry-land cropping areas of southern Australia.
• It does not tolerate competition, and can be controlled by timely cultivation and sowing of vigorous crop and pasture species.

What Does It Look Like?

What is it?

Common Heliotrope (Heliotropium europaeum) is an upright, annual herb that grows up to 40 cm high. The stems are covered in short, grey hairs. The leaves are elliptic (broadest at the middle and narrower at both ends) or ovate (egg-shaped and attached at the broadest end) and are 1.5–7 cm long and 1–3 cm wide. 

The small (up to 5 mm long), trumpet-shaped flowers are white with a yellow throat. Each flower has five small petals.

The fruit is a group of four brown nutlets, each containing one seed. The seeds are brownish, up to 2 mm long, wrinkled or warty and sometimes hairy. Up to four seeds are produced from each flower (Craven 1996; Jeans 1999).

Seedlings of Common Heliotrope have egg-shaped cotyledons (seed leaves) that are covered in very fine hairs. The first true leaves of the seedlings are oval in outline and have prominent veins on the upper surface (Dellow 2005).

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

Flower colour

White, Yellow

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

Common Heliotrope is predominantly a weed of the dry-land cropping areas of southern Australia, where it is associated with disturbed sites such as roadsides, waste places, creek beds and poor pastures. It does not tolerate competition, and is usually only found on land where other vegetation, especially perennial grasses, has been eliminated (Parsons & Cuthbertson 2001; Hunt et al. 2006). Herbarium records indicate that it grows on a range of soil types from sand to clay-loam. Common Heliotrope is very drought tolerant and is well adapted to regions that receive low rainfall (Hunt 2005).

Are there similar species?

Common Heliotrope is one of 81 species of Heliotrope that occur in Australia. Three of these species are naturalised, and the remainder are native (Craven 1996). All 81 Heliotrope species are similar and as such specialist advice should be sort to correctly distinguish Common Heliotrope from these other species.

Why Is It A Weed?

What are its impacts?

Agriculture: Common Heliotrope is poisonous to livestock (Auld & Medd 1987; Hunt et al. 2006). It is one of the most abundant and common weeds of the grain growing regions in southern Australia (Hunt 2005). In 1985 it was estimated to infest 10 million hectares of agricultural land in Australia (Culvenor 1985). It ties up nitrogen and transpires soil water that could otherwise be used by crops (Hunt et al. 2006). Common Heliotrope contains toxic alkaloids, which if ingested can cause fatalities in livestock (Parsons & Cuthbertson 2001; Hunt 2005).

How does it spread?

Seeds of Common Heliotrope spread in the same manner as similar weedy members of the Boraginaceae family, such as Paterson's Curse and Yellow Burr Weeds. Being an annual species, the sole means of reproduction is via seed. The seed is spread by water, especially where plants grow in riparian habitats and on steep terrain where erosion and run-off occurs. Contaminated soil, fodder, vehicles and cultivation equipment, as well as contaminated agricultural produce, are also significant vectors for seed transport to new sites. The hairy inflorescence and rough seed surface allow the seeds to be picked up on the wool and hair of cattle and sheep. Seeds may also be readily dispersed along roadsides during maintenance work (Baker 2008 pers. comm.).

What is its history in Australia?

Common Heliotrope was first recorded in Spencer Gulf, South Australia, in 1802. However, the specimen in question is of uncertain identity (Kloot 1983). The next record of the species was from Victoria in 1853 (National Herbarium of Victoria 2007). It was later recorded from Spencer Gulf, South Australia, in 1881, Western Australia in 1887, New South Wales in 1889 (National Herbarium of Victoria 2007) and from the Northern Territory in 1978 (State Herbarium of South Australia 2007).

Whether this species is native or naturalised in Australia is disputed. Most sources now consider it to be introduced (Hunt 2005; Bean 2007), although some believe it is native (Craven 1996).

How To Manage It?

Best practice management

Common Heliotrope can be controlled with mechanical, chemical and biological methods.

Non-chemical control: Cultivation controls seedling growth, but must be repeated to control successive germinations. Carefully timed sowing of competitive crop and pasture species will suppress regrowth of Common Heliotrope, and permanent pastures that maintain a good summer cover can gradually eliminate it (Parsons & Cuthbertson 2001).

Chemical control: The need for repeated applications of herbicides in pasture situations makes chemical control an uneconomical practice. However, chemical control can be useful as an alternative to cultivation on sites that are prone to soil erosion (Parsons & Cuthbertson 2001).

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

Biological control: Two biological control agents have been trialed, a rust fungus (Uromyces heliotropii Sred) which has had no measurable impact, and a flea beetle (Longitarsus albineus Foundras) which failed to establish under difficult conditions (NSW Agriculture 2004).

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Seeds of Common Heliotrope germinate during late spring and summer, provided that sufficient moisture is available and that there is little or no competition (Hunt et al. 2006). In the early stages of development, most of the plant's energy is directed into the production of a long taproot. This allows the seedlings to be drought hardy, even shortly after emergence. Growth continues throughout summer and autumn until plants are killed by frosts. Flowering often starts within three to four weeks of seedling emergence. Under favourable conditions Common Heliotrope will flower and produce seed throughout the summer months (Parsons & Cuthbertson 2001).

Where Is It Found?

Which states and territories is it found?

ACT, NSW, NT, QLD, SA, VIC, WA

What areas within states and territories is it found?

In Australia, Common Heliotrope is naturalised in Western Australia, South Australia, New South Wales, Australian Capital Territory, Queensland and Victoria. It is widespread in South Australia, New South Wales and Victoria (Craven 1996). In Western Australia, it is a locally abundant weed in parts of the south-west and in the eastern Goldfields (Hussey et al. 2005). It has been recorded occasionally from the Leichhardt and Darling Downs regions of Queensland (Bostock & Holland 2007) and has been recorded once in the Northern Territory (Tanami Desert) (State Herbarium of South Australia 2007). The species is absent from Tasmania. The heaviest infestations occur in the Riverina and Murray Valley in the south-eastern Australia (Parsons & Cuthbertson 2001).

Where does it originate?

Common Heliotrope is native to southern and central Europe, western Asia and northern Africa (Hussey et al. 2007).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

TAS, 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

Heliotropium europaeum

Other scientific names (synonyms)?

• Heliotropium glandulosum R.Br.
• Heliotropium lacunarium F.Muell.

Does it have other known common name(s)?

Potato Weed, Barooga Weed, Caterpillar Weed, Bishop's Beard, European Heliotrope, Wild Heliotrope, Tomato Weed, Blue Weed, Wanderrie Curse