Zantedeschia aethiopica

Zantedeschia aethiopica (known as calla lily and arum lily) is a species in the family Araceae, native to southern Africa in Lesotho, South Africa, and Swaziland.

It 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 0.6–1 m (2.0–3.3 ft) tall, with large clumps of broad, arrow shaped dark green leaves up to 45 cm (18 in) long. The inflorescences are large and are produced in spring, summer and autumn, with a pure white spathe up to 25 cm (9.8 in) and a yellow spadix up to 90 mm (3 1⁄2 in) long.

The spadix produces a faint, sweet fragrance.

Z. aethiopica is native to southern Africa in Lesotho, South Africa, Swaziland, Mozambique. It has become naturalised in Malawi, Zambia, Tanzania, Kenya, Madeira and Australia, particularly in Western Australia, where it has been classified as a toxic weed and pest.

A number of cultivars have been selected for use as ornamental plants.
'Crowborough' is a more cold tolerant cultivar growing to 90 cm (35 in) tall, suited to cool climates such as the British Isles and north-western United States.

'Green Goddess' has green stripes on the spathes which allow the flowers to last much longer than the original white form. 'Green Goddess' also has a more opened and wider spathe and has the tendency to develop curvy fringes at the edge of the spathe than the original white form. 
The first generation hybrid of 'Green Goddess' and the original white form has a light green underside on the spathe, allowing the flower to last longer than the original white form, but no green stripes on the top side.

'White Sail', growing to 90 cm tall, has a very broad spathe.
'Red Desire' has a red instead of yellow spadix and appears to be rather rare.

'Pink Mist' has a pinkish base to the spathe and pink spadix. 'Pink Mist' is not a hybrid, but a colour sport. The pink colour is best developed in semishade after rain. 'Pink Mist' is quite delicate and weak compared to the original white form and 'Green Goddess'. Unlike the latter, 'Pink Mist' has a dormant period during winter, where the leaves almost die down completely, although it is pure Zantedeschia aethiopica. The seedlings of 'Pink Mist' are also weaker than the original white form or 'Green Goddess'.

Z. aethiopica and its 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.