Arum Lily

(Also known as Calla Lily)

Zantedeschia aethiopica

Family: Araceae

Type of weed:

Flower colour(s): ,

Priority Weed Local Priority Weed. (See more weeds of the class.)

Flowering Months: , , , , , , , ,

Description

A clump-forming, perennial herb growing to 1.5m high with a thick underground stem (rhizome).

The large arrowhead-shaped leaf blades are glossy dark green to somewhat dull, leathery in texture, with a prominent midrib and a tip that is bent downwards or curls towards the underside of the leaf.

The arum-type flower structure has a central spike with tiny, tightly packed pale yellow to orange-yellow flowers. This is surrounded by a white to ivory (or green) funnel-like bract with a pointed, recurved tip. It flowers winter to summer.

Fruit is an oval, yellowish berry about 1cm in diameter.

Alert:

Arum Lily is poisonous to stock and to children. If swallowed it causes dangerous swelling of the mucous membrane of the mouth and throat. Skin contact may cause eczema.

Dispersal

Arum Lily spreads by both seed and root fragments. There may be 50 – 500 seeds per flower head. The seeds germinate readily, but do not usually remain viable for more than about four months. The seeds are spread by water, birds, foxes, contaminated soil and in dumped garden waste.

Impact on bushland

Arum Lily invades native vegetation, forms thick, dense clumps and achieves dominance along watercourses and swampy habitats. The dense clumps crowd out native species affecting the biodiversity of natural areas, especially by replacing the native understorey. In wet, swampy habitats it impedes water flow.

Distribution

. Hazelbrook, Woodford, Springwood, Winmalee, Warrimoo and across the Eastern Escarpment.

Alternative planting

Native plants

Council provides a tool, on its Mountain Landscapes website, to help you choose native alternative plantings. Choose your village, soil, vegetation community and the purpose of your planting, and the tool will give you suggestions.

There are native nurseries in several Blue Mountains villages, including Glenbrook, Lawson and Katoomba. Please also ask at your favourite local nursery.

Control

  • Hand remove
  • Remove flowers, fruit, pods or seeds
  • Manually remove bulbs, corms and tubers

Manual control

Hand remove

Grasp stem at ground level. Rock weed backwards and forwards to loosen roots, then pull out gently. Carefully tap the roots to dislodge attached soil. Replace disturbed soil and pat down.

Considerations
  • Leave weeds so that roots do not make contact with soil; on a rock, for instance. A small amount of debris may be hung in a tree or removed from the site.
  • Vary the position of your body to avoid fatigue when removing plants by hand over extended periods.

Manual removal

Move leaf litter away from base of plant. Dig down next to the stem until the bulb or tuber is reached. Remove plant and carefully bag the bulb or tuber.

Remove seeds, pods or fruit

Gently remove any seeds, pods or fruit and carefully place in a bag.

Specific control tips for this weed

Seedlings can be removed by hand. Removal of old plants is more difficult. Remove all roots and tubers (vegetative propagules).

Treat plants before they set seed and cut off the flowers to prevent spread by birds.

Follow-up treatments will be necessary.

Do not spray as this treatment is generally not effective.

For key points on these techniques:

Local Priority Weed

Control measures:

  • The plant should be fully and continuously suppressed and destroyed.
  • Plants under 4 metres in height should be fully and continuously suppressed and destroyed.
  • The spread of this plant should be adequately contained to prevent spread impacting on priority assets. Weed notices will only be issued for these weeds under special circumstances.