Canna indica (PROSEA)
Canna indica L.
- Protologue: Sp. pl.: 1 (1753).
- Family: Cannaceae
- Chromosome number: 2n= 18, sometimes 27
Canna coccinea P. Miller (1768), C. edulis Ker-Gawler (1823), C. orientalis Roscoe (1826).
- Canna, Queensland arrowroot, Indian shot (En). Balisier, canna (Fr). Achira (Sp)
- Indonesia: ganyong (Javanese, Sundanese), buah tasbeh (Javanese), ubi pikul (Sumatra)
- Malaysia: daun tasbeh, ganjong, pisang sebiak
- Philippines: tikas-tikas (Tagalog), kukuwintasan (Tagalog), balunsaying (Bisaya). Burma (Myanmar): adalut, butsarana
- Cambodia: ché:k té:hs
- Laos: kwàyz ké: so:n, kwàyz ph'uttha so:n
- Thailand: phuttharaksa (general), phutthason (northern)
- Vietnam: chuối hoa, dong riềng, khoai dao.
Origin and geographic distribution
Canna is a native to South America but is now cultivated pantropically and in other warmer regions of the world. In many regions, including South-East Asia, it has also become naturalized.
Canna produces edible rhizomes which can be eaten raw but are usually consumed after boiling or cooking in various ways. Flour can be made from the rhizomes by peeling, drying and milling. The starch is used in foods and also as sizing or laundry starch. In Vietnam, it is used for noodles. Young shoots can be eaten as a green vegetable. The leaves are suitable for wrapping and as plates. Both the leaves and the rhizomes can be used as cattle feed. Canna is also well known as a garden ornamental because of its beautiful flowers and foliage of various colours. The black and hard-coated seeds are used as beads or made into rosaries. They are also used in percussion instruments and rattles, especially in Africa.
In Java pounded seeds are used in a poultice to relieve headache. Juice extracted from grated rhizomes is used against diarrhoea. Mush made from the rhizome is taken as a remedy for yaws in Cambodia. In Hong Kong a decoction of fresh rhizomes is prescribed in acute hepatitis. Crushed fresh rhizomes are applied topically for traumatic injuries in traditional medicine in Indo-China. In the Philippines a decoction of the rhizomes is used as a diuretic and macerated rhizomes in water are applied to alleviate nose bleeding.
Fumigated stems and leaves are used as an insecticide.
Production and international trade
In Australia starch is produced from canna and traded internationally as Queensland arrowroot (about 2000-4000 t per year). World consumption, however, is very low. In South-East Asia, canna is mostly planted for home consumption and seldom enters the markets. It is most important in South America.
Per 100 g edible portion, rhizomes of C. indica contain approximately: water 75 g, protein 1 g, fat 0.1 g, carbohydrates 22.6 g, Ca 21 mg, P 70 mg, Fe 20 mg, vitamin B 0.1 mg, vitamin C 10 mg. The carbohydrates consist of more than 90% starch and about 10% sugar (glucose and sucrose). The starch produced is a shiny yellowish powder with very large (125-145μm × 60μm) irregularly shaped grains. It is highly soluble and easily digestible. After cooking, the starch is glossy and transparent.
The approximate composition of fresh leaves used as fodder is: water 90%, protein 1%, fat 0.2%, carbohydrates 7%, ash 1.4%; the digestibility is about 20%.
Rhizomatous, perennial, erect, robust herb, up to 3.5 m tall. Rhizome branching horizontally, up to 60 cm long and 10 cm in diameter, with fleshy segments resembling corms, covered with scale leaves, and thick fibrous roots. Stem fleshy, arising from the rhizome, usually 1-1.5 m tall, often tinged with purple. Leaves arranged spirally with large open sheaths, sometimes shortly petiolate; blade narrowly ovate to narrowly elliptical, up to 60 cm × 15-27 cm, entire, base rounded to cuneate, gradually attenuate to the sheath, apex acuminate, midrib prominent, underside often slightly purplish. Inflorescence terminal, racemose, usually simple but sometimes branched, bearing single or paired, irregular, bisexual flowers; bracts broadly obovate, 1-2 cm × 1 cm; sepals 3, ovate, acute, 1-1.5 cm × 0.4-0.9 cm; corolla 4-5 cm long, the lowermost 1 cm fused into a tube, lobes free; lobes 3, linear, 3-4 cm × 0.3-0.6 cm, pale red to yellow; androecium petaloid and forming the showy part of the flower, composed of an outer whorl of 3 staminodes and an inner whorl of 2 connate staminodes (one of which forms a large lip or labellum) and 1 fertile stamen; outer staminodes spathulate, 4-6 cm × 1-1.5 cm, often very unequal in length or only 2 clearly visible, fused at the base, reddish; labellum narrowly oblong-ovate, 4-5 cm × 0.5-0.8 cm, yellow spotted with red; stamen 4-5 cm long, petaloid portion involute, anther 0.7-1 cm long and adnate to the petaloid portion at base; ovary inferior, trilocular, style fleshy, 4-5 cm long, reddish, adnate at base to androecium. Fruit a loculicidally dehiscent ovoid capsule, 3 cm × 2.5 cm, outside with soft spines. Seeds numerous, globose, 0.5 cm in diameter, smooth and hard, blackish to very dark brown.
Growth and development
Rhizome cuttings develop into harvestable plants in 6-8 months after planting. In tropical regions flowering starts a few months after planting and flowers continue to appear as long as the plant lives. In regions where frost can be expected rhizomes should be lifted and overwintered at about 7°C.
A rhizome is considered mature when the triangular slit in the outer scale leaf of the rhizome has turned purple.
Other botanical information
C. indica is a problematic species complex in which flower colour as well as length, number and shape of staminodes are extremely variable. Sometimes chromosome countings of 2 n = 27 are reported (triploid species). Numerous, mainly unnamed cultivars exist. In the Andes of South America, two cultivars are well known: "Verdes" with dirty white "corms" and bright green foliage and "Morados" with violet "corms".
The present-day ornamental garden cannas are an assortment of probably over 1000 cultivars. Most of these fall into two main groups of complex hybrids: Canna × generalis L.H. Bailey (principal progenitors are C. indica , C. glauca L., C. iridiflora Ruiz & Pavon and C. warszewiczii A. Dietr.; flowers up to 10 cm diameter, not tubular at base, petals not reflexed, staminodes and labellum erect or spreading) and Canna × orchiodes L.H. Bailey (principal progenitors: C. flaccida Salisb., C. × generalis cvs Crozy cannas; flowers up to 20 cm in diameter, tubular at base, petals reflexed, staminodes wavy and exceeded by the labellum). Many cultivars are available in those hybrid complexes, with handsome yellow, pink, orange, red or variegated flowers and green, crimson, purple or variegated foliage.
Canna grows well in various climates. A well distributed annual rainfall of 1000-1200 mm is satisfactory. It seems to be daylength neutral, as it grows and flowers under a broad range of photoperiodic conditions. It is affected by drought, but tolerates excessive moisture (but not waterlogging). It is very tolerant of shade. Normal growth occurs at temperatures above 10°C, but it also survives high temperatures of 30-32°C and tolerates light frost. Canna grows from sea-level up to 1000(-2900) m altitude. It thrives on many soils, including those marginal for most other tuber crops (e.g. weathered, acidic latosols). Preferred soils are deep sandy loams, rich in humus. It tolerates a pH range of 4.5-8.0.
Propagation and planting
Canna is mostly propagated by rhizome cuttings ("corms"). Sometimes seeds are used, but because of the risk of hybridization, rhizomes are preferred to maintain the genetic identity of the clones. Young tips of rhizomes are used for vegetative propagation, not the old brown parts. Small portions of the rhizomes, bearing at least two healthy buds, are planted 50 cm apart, about 15 cm deep. Entire rhizomes can also be planted. If planted too close, the plants soon become too crowded, resulting in poor performance. It is best to plant during the rainy season, otherwise watering is needed. Canna is planted in beds that have been ploughed or dug thoroughly and mixed with plenty of manure and compost.
The edible cannas are common home garden plants in South-East Asia. In Australia, most field operations like planting, maintenance, harvesting, and milling are mechanized. Weeding is required and earthing up is recommended. Grass mulch on the beds helps to conserve the moisture in the soil and adds nutrients but may be a hiding place for beetles. Monthly manuring with liquid manure or artificial fertilizer gives better results.
Diseases and pests
Generally, canna is a hardy plant with only a few diseases and pests. Fusarium , Puccinia and Rhizoctonia spp. are possible fungal diseases. Beetles and grasshoppers may feed on the foliage, and cutworms ( Agrotis spp.) attack the rhizomes.
Plants are pulled or dug out for the rhizomes. Plants grown from rhizome tips can be harvested 4 months after planting, but harvesting after 8 months gives higher yields, because then the rhizomes have swollen to their maximum. Rhizomes should not be allowed to become much older than 10 months as they become tough and less suitable for consumption or starch production.
Rhizome yield ranges from 23 t/ha at 4 months to 45-50 t/ha at 8 months, to 85 t/ha after a year. Reported starch yields are 4-10(-17.5) t/ha.
Handling after harvest
The freshly harvested rhizomes should be handled with care. As they are mainly consumed locally, the time between harvesting and consumption is usually short. For the commercial production of flour, rhizomes are processed immediately after harvesting. To obtain the starch the rhizome is grated, water is added and the fibrous pulp is decanted. Cleaned rhizomes can be stored safely for several weeks under cool and dry conditions. To store rhizomes for longer periods, they should be kept frost-free but not too dry (in Japan, for example, in pits 30 cm deep in the field).
There are many species and cultivars of Canna L. and the genus seems to be in no danger of genetic deterioration. However, it is important to conserve older and less popular cultivars and clones, to conserve the vast genetic diversity. No comprehensive germplasm collections exist at present.
Selection among locally available cultivars should be a first step to improve the crop. Manual cross-pollination for the production of new hybrid cultivars is possible. Hybridization of canna is presently done solely for the purpose of producing new ornamental cultivars.
Canna is currently utilized locally only and not widely traded, but prospects for improvement are promising. Commercial production of canna flour under the name of Queensland arrowroot in Queensland, Australia, shows that this crop can be of commercial value to other countries as well. Research may uncover markets for its valuable starch, e.g. in easily digestible speciality foods. Systematic plant breeding is needed to improve rhizome yield and quality.
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- National Research Council, 1989. Lost crops of the Incas: little-known plants of the Andes with promise for worldwide cultivation. National Academy Press, Washington, D.C., United States. pp. 26-37.
- Ochse, J.J. & Bakhuizen van den Brink, R.C., 1980. Vegetables of the Dutch East Indies. 3rd English edition (translation of "Indische Groenten", 1931). Asher & Co., Amsterdam, the Netherlands. pp. 95-96.
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- Segeren, W. & Maas, P.J.M., 1971. The genus Canna in northern South America. Acta Botanica Neerlandica 20: 663-680.
H.C. Ong & J.S. Siemonsma