Zantedeschia aethiopica
Zantedeschia aethiopica, commonly known as calla lily and arum lily, is a species of flowering plant in the family Araceae, native to southern Africa in Lesotho, South Africa, and Eswatini. Description. "Zantedeschia aethiopica" is a rhizomatous herbaceous perennial plant, evergreen where rainfall and temperatures are adequate, deciduous where there is a dry season. Its preferred habitat is in streams and ponds or on the banks. It grows to tall, with large clumps of broad, arrow shaped dark green leaves up to long. The inflorescences are large and are produced in spring, summer and autumn, with a pure white  spathe up to and a yellow spadix up to long. The spadix produces a faint, sweet fragrance. "Zantedeschia aethiopica" contains calcium oxalate, and ingestion of the raw plant may cause a severe burning sensation and swelling of lips, tongue, and throat; stomach pain and diarrhea may occur. Distribution and habitat. "Z. aethiopica" is native to southern Africa, specifically Lesotho, Mozambique, South Africa, and Eswatini. It has naturalised in Kenya, Madeira, Azores, Malawi, New Zealand, Tanzania, Zambia, coastal California and Australia, particularly in Western Australia, where it has been classified as a toxic weed and pest. The cultivar 'Green Goddess' is  listed in the New Zealand National Pest Plant Accord, which proscribes its cultivation, sale, and distribution. Cultivation and uses. A number of cultivars have been selected as ornamental plants: The cultivars 'Crowborough' and 'Green Goddess' have gained the Royal Horticultural Society's Award of Garden Merit. In order to introduce colours to the large white calla lilies, like the many colours available in the dwarf summer calla lilies, attempts have been made to hybridise "Z. aethiopica" with "Z. elliotiana". These have resulted in albino progeny, which are non-viable. "Zantedeschia aethiopica" can be used for treatment of wastewater due to  its tolerance of iron and ability to grow in wet areas. Symbolism. "Zantedeschia aethiopica" is the national flower of the island nation of Saint Helena, where it grows widely. Further, it is an important symbol of Irish republicanism and nationalism since 1926, because it is used to commemorate the dead of Easter 1916 and onward.