Since the 1980s, research has been conducted to determine the feasibility of using Zantedeschia species as flow- ering potted plants. In addition, many calla hybrids have been bred for forc- ing as flowering potted plants (van Scheepen, 1991). Funnell (1993) pro- Crop vides a list of 61 species and cultivars commercially available internationally. About 50% of flowering size calla tu- bers are produced in the United States, Reports 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 The genus Zantedeschia is a part calla are grown as flowering potted Calla History and of the Araceae family. There are seven plants whereas in Europe about 80% to Culture recognized species and two subspecies 85% are used as cut flowers. of Zantedeschia: Z. aethiopica (L.) Spreng., Z. rehmannii Engl., Z. Genetics and cultivar development Jeff S. Kuehny1 jucunda Letty, Z. elliottiana (Watson) Engl., Z. pentlandii (Watson) Wittm., Natural species and hybrids of Z. odorata P.L. Perry, Z. albomaculata calla are diploid with 32 chromosomes (Hook.) Baill. subsp. albomaculata, Z. (Cohen and Yao, 1996). There are a ADDITIONAL INDEX WORDS. Zantedeschia, albomaculata (Hook.) Baill. subsp. number of postfertilization botany, taxonomy, cultural require- macrocarpa (Engl.) Letty, and Z. incompatability barriers between spe- ments, pests, postproduction, post- albomaculata (Hook.) Baill. subsp. cies with most calla being self fertile. harvest valida Letty. (Letty, 1973; Perry, Development in the United States has alla is a tropical plant na- 1989). Closely related genera are been concentrated in California, Luther tive to Africa extending Aglaonema Schott., Anthurium Burbank made crosses within the ge- from Cape Province to East- Schott., Caladium Venten., nus Zantedeschia and produced several C Dieffenbachia Schott., Epipremnum new cultivars at the turn of the century ern Orange Free State, Natal, Lesotho, Swaziland, Transvaal, Rhodesia, Schott., Monstera Adans., Nephthytis (Welsh, 1991). In the 1940s and 1950s Malawi, Zambia, Angola, and into Schott., Philodendron Schott., Shibuya (1956), also in California, northern Nigeria (Letty, 1973; Tjia, Spathiphyllum Schott., and Syngonium conducted extensive intercrossing work 1985). The genus Zantedeschia was Schott. (Liberty Hyde Bailey with Z. rehmannii, Z. albomaculata, assigned to calla by Sprengel in 1826 Hortorum, 1976). and Z. elliottiana. His breeding work in honor of Italian botanist Giovanni Calla have two different types of produced spathe coloration covering Zantedeschia (Letty, 1973). storage organs (Funnell, 1992). almost the entire color scale along There are many common names Zantedeschia aethiopica have stemless with variations in the shape and size of and several species. Common names rhizomes and are an evergreen species. leaves and the tubers, the pattern and include calla lily, pig lily, arum lily, The remaining species have compact distribution of leaf spots, plant growth aroid lily, zantedeschia, richardia, cape stems or tubers and are deciduous. and plant heights. In New Zealand, arum, cape lily, black-eyed arum, yel- The leaves are entire and born on a breeding has been conducted by low arum, cuckoo-pint, jack-in-the- long petiole. The inflorescence is com- Brljevich of Maungaturoto in 1932, pulpit, lily of the Nile (Funnell, 1993; posed of a fleshy spadix bearing the Matthews of Waikanae started collect- Hoogasian, 1992; Tjia, 1985). Other true flowers, subtended by a single ing and breeding in 1946, and Harrison common names of calla include showy spathe (Corr, 1993; Corr and conducted breeding in the 1960s kleinvarkblom, varkblomme, varkore, Widmer, 1987; Liberty Hyde Bailey (Welsh, 1991). The Brown family of aronskelke, persvarkoor, varkoorlelie, Hortorium, 1976; Tjia, 1985). Central California began breeding calla varkore (Funnell, 1993). Calla may be grown as outdoor in the 1940s; however, homogeneous garden plants, commercial cut flowers seed strains were not readily obtained, and more recently as flowering potted and the new hybrids were sold as mixed Assistant professor, Department of Horticulture, Loui- siana State University Agricultural Center, 137 Julian plants. Although this plant has not hybrids for many years ( Brown, 1990). C. Miller Hall, Baton Rouge, LA 70803-2120. been widely grown commercially, there The inability of growers to control Approved for publication by the director of the Loui- is an abundance of information on all bacterial soft rot [Erwinia carotovora siana Agricultural Experiment Station as manuscript aspects of calla and it continues to subsp. carotovora (Jones) Bergey et no. 99-28-0290. Company, plant or chemical names are referred to for example only and it is not the intent increase in popularity. Zantedeschia al.] and poor seed collection, decreased of the author to promote the use of any particular brand elliotiana, Z. aethiopica, and Z. demand, production and breeding in or company. The cost of publishing this paper was rehmannii have been grown for cut the 1960s and 1970s. Cultural tech- defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby flower production or outdoor garden niques for preventing and suppressing marked advertisement solely to indicate this fact. plants for many years (Post, 1959). disease infestation, the development ● April–June 2000 10(2) 267 CROP REPORTS of tissue culture, the development of ground during winter) (Letty, 1973; scape plant ( Letty, 1973; Funnell, true F1 seed lines in the United States Tjia 1985). 1993; Perry, 1989; Tjia, 1989). and a demand for wide range of plants The evergreen species Z. Zantedeschia elliottiana has de- and flowers has revived the calla indus- aethiopica with, ovate-cordate solid ciduous, orbicular-ovate leaves and try and breeding programs. Current green leaves and white spathes at least yellow to gold colored spathes that are breeding programs select for use as 36 inches (100 cm) tall has long been about 12 inches (30 cm) tall, bloom- flowering pot plants and cut flowers. used for cut flowers and container ing in the summer ( Funnell, 1993; Breeders are using the existing hybrids plants (Fig. 1). It flowers in summer Tjia, 1989; Tjia, 1985; Letty, 1973). and species and are breeding for: plant and late fall into early spring in frost Zantedeschia pentlandii (syn. Z. height, a large number of spathes free areas (Letty, 1973; Dole and angustiloba) has deciduous, oblong- (multibranching), spathe size, ease of Wilkins, 1999; Tjia and Funnell, 1986). elliptic to oblong-lanceolate leaves culture, disease resistance, ability to Cultivar selections include the dwarf usually without white spots (Fig. 4). force, fragrance, stem strength and selection ‘Childsiana’, ‘Pink Mist’ a Spathes can be white, cream, ivory, post production longevity (Brown, pink spathe selection, and ‘Green God- pale greenish yellow or yellow, usually 1990; De Hertogh, 1996; Funnell, dess’ with a green spathe. The species with a purple blotch at the base, are up 1993). Golden State Bulb Growers has naturalized (perennialized) in many to 24 inches (60 cm) tall and bloom in (Watsonville, Calif.) has, for example, countries, e.g., New Zealand, Austra- the summer ( Letty, 1973; Funnell, introduced 12 new true F1 hybrid seed lia, Mexico, and California. (Dole and 1993; Tjia, 1989). lines over the last 10 years (T. Lukens, Wilkins, 1999; Tjia, 1985). Zantedeschia odorata has decidu- personal communications). In addi- Zantedeschia aethiopica have solid ous, ovate to cordate leaves with milk- tion, in vitro chromosome doubling of green leaves and is the only species to white spathes having a green base and calla by induction of polyploid strains have long, branched rhizomes. All sweet scent (Funnell, 1993; Perry, has been reported by Cohen and Yao other species have compact, disk- 1989). (1996). The combinations of these shaped stems referred to as tubers Zantedeschia albomaculata has de- efforts will potentially increase the (Letty, 1973). ciduous, triangular-hastate leaves and range of hybrids that can be produced. Zantedeschia rehmannii has de- the spathe color ranges from creamy to ciduous, narrow, lanceolate leaves straw colored to pale yellow, with Species and cultivars which are neither spotted nor lobed purple interior bases; flower stems can More than 10 species have been (Fig. 2). The 24 inch (60 cm) tall be up to 18 inches (45 cm) tall (Funnell, proposed for the genus Zantedeschia spathes bloom in summer and range in 1993; Tjia, 1985). (Traub, 1948), later reduced to six color from yellow to lemon yellow and Zantedeschia albomaculata sub. (Letty, 1973). A recent addition brings pink to dark maroon (Letty, 1973; albomaculata has deciduous, oblong- the current number to seven (Perry, Funnell, 1993; Tjia, 1985). hastate leaves, and a plant height of up 1989), with two subspecies (Funnell, Zantedeschia jucunda has decidu- to 30 inches (75 cm) (Fig. 5). The 1993; Letty, 1973). The species fall ous, triangular-hastate leaves that are spathes are white, ivory, pale yellow, to into two specific groups: 1) evergreen always spotted (Fig. 3). Spathes are coral pink, bloom in the summer and (plants with foliage that does not die golden yellow with a purple throat at are not widely used commercially down in the winter) and 2) deciduous the base and are summer blooming. (Letty, 1973; Funnell, 1993; Tjia, (plants with foliage that dies to the This species