Zantedeschia is a genus of flowering herbs native to southern Africa, with eight species commonly called calla lily or arum lily. Somewhat confusingly, Zantedeschia is not a true lily and is distinct from the genera Arum and Calla. Zantedeschia plants are cultivated as ornamental plants for their large, funnel shaped flowers, which may be pink, white, orange, red, purple, or yellow. The plants are toxic and can cause swelling of the throat and gastrointestinal problems, though the leaves of some species are cooked as food.
Plants in this genus require abundant water and fertilizer, as well as warm temperatures. Some species are tolerant of cooler temperatures or light frosts, while others can only be grown as houseplants in cooler climates. Z. aethiopica, or the common arum lily, is the hardiest species and the most widely cultivated. It has become invasive in some areas, particularly in Australia, where is has become naturalized.
Also called calla lily or Easter lily, Z. aethiopica features white flowers with a yellow spadix or spike in the center. There are many cultivated garden varieties with different colored flowers, including red desire, green goddess, and pink mist. The spring blooming flowers are traditionally displayed during Easter, particularly in the British Isles.
Zantedeschia elliottiana, commonly called the yellow or golden arum lily, is a summer blooming species with bright yellow flowers. The flowers sometimes mature into berries of the same color that attract bird pollinators. Z. elliottiana is grown ornamentally, and is not known in the wild. It may have developed as a hybrid of other species.
Zantedeschia rehmanii is known as the pink calla or pink arum lily for its bright pink to purple blooms. It is somewhat tolerant of frost, though not as hardy as Z. aethiopica. The pink calla lily requires partial shade and protection from winds.
Rarer species of Zantedeschia include Z. jucunda, Z. odorata, and Z. pentlandii. Z. jucunda and Z. pentlandii have bright yellow flowers, while Z. odorata features fragrant white flowers, similar in appearance to those of Z. aethiopica. Z. odorata grows only in limited areas of South Africa and has a scent reminiscent of freesia. Z. albomaculata, on the other hand, is widespread throughout Africa, growing as far north as Kenya, and has white to orange flowers. There are many Zantedeschia hybrids in cultivation as well, most developed by horticulturalists in New Zealand and California, where the plants grow well.