Photo guide to weeds

Tobacco weed (Elephantopus mollis)

  • Photo of the Tobacco Weed
    Tobacco weed flower.
  • Photo of the Tobacco Weed
    Tobacco weed.

General information

Tobacco weed is a vigorous and aggressive weed and is regarded as a serious weed of agriculture in many wet tropical or subtropical countries.

Tobacco weed is a declared Class 2 pest plant under Queensland legislation.

Scientific name Elephantopus mollis
Similar species

Elephantopus scaber

Description
  • Slender, fast-growing herb reaching up to 150cm high
  • Leaves are oblong or oval, 10-20cm long and 2-5cm wide, occurring mostly at the base.
  • Leaves upper surfaces are rough and thinly covered in fine hairs. The undersurfaces are densely haired and resinous, especially on veins.
  • Flowers are small, white and are in many-headed clusters at tips of stems and side shoots.
  • Three small leaf-like bracts cup each cluster. Individual flowers are tubular with five lobes at the apex and are about 4mm long.
  • Stem is more or less erect and sparsely branched, becoming woody at the base when mature. Covered with fine white hairs, it may cause skin irritation when brushed against.
  • Seeds are brown to greyish-black, 3mm long, each with five fine, straight, white, bristle-like hairs on top.
Habitat
  • Native to tropical regions in the Americas.
  • Grows in fertile soils needing moderate to high rainfall. 
Distribution
  • Currently found in the Millaa Millaa area on the southern Atherton Tableland, at Cape Tribulation in Far North Queensland, Koumala district south of Sarina and around Teemburra Dam to the west of Mackay.
  • Spread to most tropical regions around the world.
Life cycle
  • Seeds can germinate any time of the year if sufficient moisture.
  • Flowering may also occur all year, but generally occurs in May.
  • Germination to reproduction time and the time ungerminated seeds remain viable are not known; however, field observations indicate that seed banks build up in the soil.
Spread
  • Seeds spread primarily by animals, machinery and running water.
Impacts
  • Smothers healthy thick pastures with dense masses of broad-leafed seedlings.
  • Major threat to the beef and dairy industries of North Queensland.
Prevention

The best form of weed control is prevention. Treat weed infestations when they are small - do not allow weeds to establish.

Steps for weed prevention:

  • Check your property regularly for suspect plants.
  • Control new infestations before they spread and become a major problem.
  • Don't dump weeds and garden waste in bush or parkland.
  • Know the weed status of any products or materials you are receiving. This includes fodder, grain, gravel, machinery, mulch, packing material, sand, soil, stock, vehicles and water.
  • Clean your equipment, clothing, shoes, vehicles and machinery when leaving natural habitats and camping areas.
  • Use a cleandown facility to blow, vacuum or wash dirt and seeds from vehicles, machinery and tools.
  • Request a weed hygiene declaration from your suppliers.
  • Ensure vehicles and machinery are clean before entering your property.
Control

Physical control

  • Controlled by cultivation.
  • As no underground buds are produced, fire could kill a significant number of plants and may be a useful tool during the dry season.

Mechanical control

  • Slashing has been used to switch reproductive plants back to the vegetative mode, to allow treatment with herbicide.

Herbicide control

  • Spray plants before they develop flowering stems.
  • Aerial spraying is an option when plants are inaccessible, but every care needs to be taken to prevent drift onto remnant and regenerating rainforest in the margins of the paddocks.
  • Difficult to control once the plant has begun to flower (and possibly as early as at the beginning of stem growth).
  • See the tobacco weed fact sheet (PDF, 242 kB) for herbicide control and application rates.

Biological control

  • There is no biological control agent available for tobacco weed.
Declaration details
  • A declared Class 2 species under the Land Protection (Pest and Stock Route Management) Act 2002.
  • Taking for commercial use, introduction, keeping, releasing and supplying (including supplying things containing reproductive material of this pest) is prohibited without a permit issued by Biosecurity Queensland.
  • Landholders are required to control declared pests on their properties.

Last updated 09 April 2013