Also known as
Alocasia macrorrhiza, Alocasia indica
Where is it originally from?
What does it look like?
Large perennial (<3 m tall) with a thick, fleshy rhizome with milky sap. Mature plants have thick, trunk-like stems (5 m x 30 cm) with leaf scars and the lower part of the stem usually lies along the ground. Shiny, leathery, deep green arrow-shaped leaves (80 x 50 cm) have prominent veins, and occasionally have white patches. Fragrant creamy-yellow to orange flower spikes (<15 cm long) are held inside green boat-shaped bracts (<5 cm long) and develop into scarlet or orange berries.
Are there any similar species?
Taro (Colocasia esculenta) has smaller leaves on long stalks with a reddish-purplish tinge.
Why is it weedy?
Long-lived, smothers ground in damp sites on most soil types, and persists under regenerating canopy in dense patches. Drought-resistant once established, and recovers from heavy damage. Stock avoid it as it is poisonous, so it dominates grazed sites.
How does it spread?
Limited distribution through seed drop near to parent plants, and occasionally through water. Clumps expand slowly through new shoots. It can be spread by intentional planting, dumped vegetation, and soil movement.
What damage does it do?
Smothers the ground, preventing the seedlings of native species from establishing. It is unlikely to poison native fauna.
Which habitats is it likely to invade?
Wetlands, streamsides, river systems, heavily disturbed shrubland and forest, damp frost-free open areas, and regenerating ex-pasture.
What can I do to get rid of it?
Begin clearance at top of catchment.
1. Hand pull small seedlings in high light areas.
2. Slash tops, Leave on site to rot down. Dig out tubers, bury deeply, or dispose of at a refuse transfer station.
3. Stump paint: Slash near ground level and treat fresh stumps with metsulfuron-methyl 600g/kg (1g) + glyphosate (100ml ) + penetrant per 1L.
4. Spray: metsulfuron-methyl 600g/kg (3g) + glyphosate (150ml) + penetrant per 10L.
What can I do to stop it coming back?
Digging usually leaves rhizome fragments and plants will always regrow after slashing. Exclude all livestock from site when treating. Follow up annually.