yellow showy flowers. Z. rehmannii is a pink-flowered species with sword shaped leaves. Z. elliotiana is known from horticultural sources only and is probably of hybrid origin. Introduction Zantedeschia was introduced to Europe in the seventeenth century as Z. aethiopica, and is now widely naturalised in Europe, North America, Central America, South America, Oceania, and Australasia. In many places it is considered a dangerous invasive species that displaces native vegetation. In the South-West of Western Australia, Z. aethiopica was introduced for horticulture, but has become a widespread and conspicuous weed of watercourses, heath, and wet pastures to the extent that it has been declared a pest in Western Australia and landowners must control it and attempts to sell plants must be reported. Zantedeschia in North America is primarily grown as ornamental cultivars in home gardens. Habitat Z. aethiopica grows naturally in marshy areas and is only deciduous when water becomes scarce. It grows continuously when watered and fed regularly and can survive periods of minor frosts. Z. aethiopica is a very strong and sturdy plant, being able to grow in many soils and habitats, multiplying by rhizome-offsets. Cultivation All Zantedeschia produce large, showy flowers spathes and are often grown both as ornamental plants and for cut flowers. Zantedeschia are relatively hardy plants, but some are more winter-hardy than others. In this regard there may be considered two groups, a hardy outdoor group with large white flowers (arum lilies) and less hardy group with white-spotted leaves and flowers in many colours (calla lilies), such as yellow, orange, pink and purple. Hardy forms (arum lilies) These include Zantedeschia aethiopica and Zantedeschia pentlandii and their cultivars. Zantedeschia aethiopica and some of its relatives can survive at minimum winter temperatures below -23 °C (USDA Zone 6) and many others can be grown in even warmer areas where all the ground does not freeze (USDA Zone 7). Z. pentlandii hybrids include 'Millennium Gold'. Tender forms (calla lilies) The more tender specimens are mainly cultivars (hybrids) of Zantedeschia elliotiana and Zantedeschia rehmannii (referred to as elliotiana or rehmannii cultivars or hybrids, or as e.g. Z. × rehmanii), but also Zantedeschia albomaculata and Zantedeschia jucunda. These less hardy forms can only survive winter temperatures to −12 °C (Zones 8). This plant must be grown as tender bulbs or houseplants in cooler areas. Species and hybrids between Z. elliotiana, Z. jucunda, Z. pentlandii and Z. rehmannii appear to