Zantedeschia aethiopica (arum lily)

The arum lily is native to Southern Africa (provinces of Limpopo, North-West, Gauteng, Mpumalanga, Swaziland, Free State, KwaZulu-Natal, Lesotho, Western Cape and Eastern Cape), where it grows in marshy places from 20 to 2250 metres above sea level. It is also widely naturalized throughout the tropics.

Arum lilies in Wolfgat Nature Reserve, Cape Town, South Africa (Image: Wolfgang Stuppy)

Due to its striking inflorescences, Zantedeschia aethiopica is very popular as cut flowers and as an ornamental. It is used as a symbol of purity in bridal and funeral flower arrangements.

In southern Africa where it occurs naturally, the leaves and rhizomes are traditionally used in dressings and oral preparations for a variety of complaints. The rhizomes are edible, although the plant is reportedly toxic.

Scientists have shown that Zantedeschia aethiopica may be useful in artificial wetland systems to clean waste water and prevent algal growth.

Zanthedschia aethiopica (Image: Wolfgang Stuppy)

This moderately hardy monocot can be grown outside in the UK, but at Kew is sheltered under the glass of the Temperate House. In any position it will grow best in moist soil or shallow water. In its natural habitat it can be deciduous or evergreen, depending on the rainfall and soil water rather than temperature. The position in which it is planted will also determine size and flowering. Planting under shade is preferable if there is no boggy position for this plant, but this will reduce the number of flowers and result in a smaller plant. Fertile soil is required. In optimum conditions a good display of flowers can be enjoyed in the spring and summer.

Propagation can be by seed or division. Seeds can be removed from the pulp of the fruit when it has turned yellow and soft. The seeds should then be dried off for sowing in the spring. They should be sown sparingly to allow space for the fleshy roots to form. A seed compost should be used and the seeds covered lightly. Division of the fleshy rootstock should be done when the plant is dormant. It can then be planted at a depth of 5 cm.

Kew's Millennium Seed Bank partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Number of seed collections stored in the Millennium Seed Bank: 1
Germination testing: Successful

You can see Zantedeschia aethiopica growing at Kew in the Duke's Garden, on the south side by the wall.

Kew's work in South Africa with the Cape arum lily

PlantZAfrica.com - provides information about plants native to southern Africa and related topics.

Search Kew's databases for more information on this species