Calla is a tropical plant native to Africa extending from Cape Province to Eastern Orange Free State, Natal, Lesotho, Swaziland, Transvaal, Rhodesia, Malawi, Zambia, Angola, and into northern Nigeria (Letty, 1973; Tjia, 1985). The genus Zantedeschia was assigned to calla by Sprengel in 1826 in honor of Italian botanist Giovanni Zantedeschia (Letty, 1973). There are many common names and several species. Common names include calla lily, pig lily, arum lily, aroid lily, zantedeschia, richardia, cape arum, cape lily, black-eyed arum, yellow arum, cuckoo-pint, jack-in-thepulpit, lily of the Nile (Funnell, 1993; Hoogasian, 1992; Tjia, 1985). Other common names of calla include kleinvarkblom, varkblomme, varkore, aronskelke, persvarkoor, varkoorlelie, varkore (Funnell, 1993). The genus Zantedeschia is a part of the Araceae family. There are seven recognized species and two subspecies of Zantedeschia: Z. aethiopica (L.) Spreng., Z. rehmannii Engl., Z. jucunda Letty, Z. elliottiana (Watson) Engl., Z. pentlandii (Watson) Wittm., Z. odorata P.L. Perry, Z. albomaculata (Hook.) Baill. subsp. albomaculata, Z. albomaculata (Hook.) Baill. subsp. macrocarpa (Engl.) Letty, and Z. albomaculata (Hook.) Baill. subsp. valida Letty. (Letty, 1973; Perry, 1989). Closely related genera are Aglaonema Schott., Anthurium Schott., Caladium Venten., Dieffenbachia Schott., Epipremnum Schott., Monstera Adans., Nephthytis Schott., Philodendron Schott., Spathiphyllum Schott., and Syngonium Schott. (Liberty Hyde Bailey Hortorum, 1976). Calla have two different types of storage organs (Funnell, 1992). Zantedeschia aethiopica have stemless rhizomes and are an evergreen species. The remaining species have compact stems or tubers and are deciduous. The leaves are entire and born on a long petiole. The inflorescence is composed of a fleshy spadix bearing the true flowers, subtended by a single showy spathe (Corr, 1993; Corr and Widmer, 1987; Liberty Hyde Bailey Hortorium, 1976; Tjia, 1985). Calla may be grown as outdoor garden plants, commercial cut flowers and more recently as flowering potted plants. Although this plant has not been widely grown commercially, there is an abundance of information on all aspects of calla and it continues to increase in popularity. Zantedeschia elliotiana, Z. aethiopica, and Z. rehmannii have been grown for cut flower production or outdoor garden plants for many years (Post, 1959). Since the 1980s, research has been conducted to determine the feasibility of using Zantedeschia species as flowering potted plants. In addition, many calla hybrids have been bred for forcing as flowering potted plants (van Scheepen, 1991). Funnell (1993) provides a list of 61 species and cultivars commercially available internationally. About 50% of flowering size calla tubers are produced in the United States, The Netherlands and New Zealand produce 45% and India, Sri Lanka, and Central America produce 5% (T. Lukens, personal communications). In the United States, more than 95% of calla are grown as flowering potted plants whereas in Europe about 80% to 85% are used as cut flowers.