Elephant's ear
Aracae (Arum) - Aloasia brisbanensis

What does it look like?

Elephant's ear is a robust perennial that is native to the rain forests of Queensland, Australia.  It has thick stems up to 1.2m long and large, wide arrow-shaped leaves that reach 50-75cm in length.  Mature plants have 4-5 large leaves, and can form dense stands reaching 1-2m in height.  The plant produces erect, cream-coloured and very fragrant flowers up to 6cm long surrounded by a light green sheath up to 15cm long.  Flowers are produced in the summer months from January to April.  The leaves of the plant die back in spring, and fruiting occurs in September with small orange or scarlet berries of 10mm in diameter clustering on the flower stalks, each with one to four seeds.  It has thick rhizome rootstock that is poisonous (although it can be eaten if properly cooked).

Elephant's ear prefers wet or damp areas such as wetlands, riverbanks or damp open areas, and will also grow in regenerating former pasture or heavily disturbed shrubland and forest.  It prefers frost-free areas.

 

Why is it a problem?

This plant is long-lived and can out-compete other species as it smothers areas in damp sites.  Once established it is drought resistant, and is avoided by stock as it is poisonous, so can dominate grazed sites.  It has the potential to become more common and a problematic environmental weed.

Produces seed that is dropped below the adult plant or is spread by birds, and can also reproduce via disturbed roots or fragments.

Vectors of spread: Vegetative spread or by bird.  Spread can be exacerbated by human removal, dumping or through soil movement. Plants will regrow after slashing, and it can regrow from fragments.

Control Methods

Begin clearance at top of catchment.

Physical control

  • Hand pull small seedlings in areas of high natural light.
  • Digging of larger plants usually leaves rhizome fragments which can regrow, thus herbicide control is recommended.

Herbicide control 

  • Stump paint: Cut near ground level and treat fresh stumps with 1g metsulfuron-methyl (600 g/kg) per 1L water. Ensure any rhizomes cut off are either mulched finely or dried and burnt or deep buried. 
  • Weed wipe: 1g metsulfuron-methyl (600g/kg) per 1L water.
  • Spray: 5g metsulfuron-methyl (600g/kg) + 10ml penetrant/10L.

Exclude all livestock from site when treating. Follow up annually.

CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.