Zantedeschia is a genus of flowering plants in the family Araceae. They are indigenous to South Africa but also occur north towards Malawi. The name of the genus was given as a tribute to Italian botanist Giovanni Zantedeschi. Common names include arum lily, calla and calla lily although it is neither a true lily (Liliaceae), nor an Arum or a Calla (related genera in Araceae). In Afrikaans some common names include aronskelk and varkoor. It has often been used in paintings, and is visible in many of Diego Rivera’s works of art. It was a favourite subject of the painter Georgia O’Keeffe. Zantedeschia species are rhizomatous herbaceous perennial plants growing to 1-2.5 m tall with leaves 1545 cm long. The inflorescence is a showy white, yellow or pink spathe shaped like a funnel with a yellow, central, finger-like spadix. Currently 8 true species are recognized, these being Zantedeschia aethiopica (Giant White Arum Lily or Common Arum Lily), Zantedeschia albomaculata (Spotted Leaved White Arum Lily), Zantedeschia elliottiana (Yellow or Golden Arum Lily), Zantedeschia jucunda, Zantedeschia odorata, Zantedeschia pentlandii, Zantedeschia rehmannii (Pink Arum Lily) and Zantedeschia valida. All Zantedeschias produce large, showy flowers spathes and are often grown both as ornamental plants and for cut flowers. Zantedeschia are cold hardy plants, but some are more winter-hardy than others. The white Zantedeschia aethiopica and some of its relatives can survive at minimum winter temperatures below -23°C. Zantedeschia aethiopica is one of the world’s most iconic and widely-known plants. Although commonly known as the arum lily or calla lily, it is not a lily at all but an aroid, with its brilliant white spathe (floral bract) surrounding the central pale yellow spadix (floral spike) bearing tiny flowers. The arum lily is well known for its striking appearance when in flower, with a brilliant white floral bract wrapping around a yellow finger-like projection in the centre. The flowering parts arise from a ring of glossy green leaves. The fruits are green berries which turn orange at the base when ripe. 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. It is cold hardy to -23°C. Scientists have shown that Zantedeschia aethiopica may be useful in artificial wetland systems to clean waste water and prevent algal growth.
