Zantedeschia aethiopica (Arum lily)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Monocots 
Order: Alismatales 
Family: Araceae 
Subfamily: Aroideae 
Tribe: Zantedeschieae 
Genus: Zantedeschia 
Species: Z. aethiopica
Binomial name: Zantedeschia aethiopica 
Common name: Lily of the Nile, Calla lily, It is also commonly known as the Arum lily, although the plant is not a true Arum

It is a rhizomatous herbaceous perennial plant a native from South Africa. It is an evergreen found in swampy areas and damp wasteland. It grows to 0.6-1 m tall, with large clumps of broad, arrow shaped dark green leaves up to 45 cm long. The Inflorescences are large, produced in spring, summer and autumn, with a pure white spathe up to 25 cm and a yellow spadix up to 90 mm long.
Zantedeschia aethiopica is native to southern Africa in Lesotho, South Africa, and Swaziland. The plant has been classified as a toxic weed and is a declared pest. It Impacts by smothering the ground layer preventing regeneration of natural flora.
Zantedeschia is highly toxic and may be fatal if eaten. All parts are poisonous, including the ripe spike of berries in the middle of the flower. Ingestion may cause a severe burning sensation and swelling of lips, tongue, and throat; stomach pain and diarrhoea are possible.
It is classed by New Zealand Biosecurity as a pest plant. It smothers ground, preventing regeneration of native flora. All parts of the plant poisonous to humans, pets and livestock. Seeds mainly spread by birds. Flowing water, animals also play a role. Local spread by rhizomes. Dumping of garden cuttings. 

Zantedeschia aethiopica Calla lily.JPG

Zantedeschia aethiopica Calla lily-4.JPG

Zantedeschia aethiopica Calla lily-5.JPG

A dying petal exposing the ripe stigma
Stigma of Zantedeschia aethiopica Calla lily-4.JPG

This video is on the poisonous properties of all species of the arum lily.VIDEO

Thanks to Wikipedia for text and information: