Chrysanthemum coronarium (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Chrysanthemum coronarium L.

Protologue: Sp. pl.: 890 (1753).

Family: Compositae

Chromosome number: 2n= 18; 36 (tetraploid)

Synonyms

• Matricaria coronaria (L.) Desr. (1792),
• Pinardia coronaria Lessing (1832),
• Chrysanthemum spatiosum L.H. Bailey (1949).

Vernacular names

• Garland chrysanthemum, crown daisy, tangho (from Chinese) (En)
• Shungiku (from Japanese), chop suey green, Japanese green (Am)
• Chrysanthème des jardins (Fr)
• Indonesia: tango, saruni walanda (West Java)
• Philippines: tango (Tagalog)
• Laos: tang 'ôô
• Thailand: phaktang-o (central), phakkhikhwai (northern)
• Vietnam: cải cúc, cúc tần ô.

Origin and geographic distribution

C. coronarium is native to the Mediterranean region and is distributed throughout Europe, northern Africa, and Asia. It has long been cultivated in Europe and Asia, but for different purposes: in the western world mainly as an ornamental, in Asia (China, Japan) mainly as a vegetable. In South-East Asia, the vegetable types were probably introduced from China relatively recently, as the Chinese-derived name "tangho" has remained strongly associated with the crop in most countries.

Uses

The aromatic leaves and young shoots of tangho have a spicy, slightly resinous, "floral" taste. The Chinese and Japanese are especially fond of this vegetable. The small-leaf types have a very strong taste and are eaten cooked or fried, often together with other vegetables or in soups. The large-leaf types can in addition be eaten raw in salads. When the leaves are cooked too long, they become very bitter. The flowers are also edible. Usually only the petals are used, fresh or dried, as a garnish or to brew a tea. Tangho is also consumed in the form of seedling sprouts.

In Thailand, it is used as a medicinal plant to cure venereal diseases. C. coronarium or garland chrysanthemum is an old-fashioned ornamental in Europe. Special forms with double ray flowers, and larger-sized tetraploids (2n = 36?) have been developed.

Production and international trade

Tangho is one of the leading greens in East Asian countries (Japan, China, Taiwan) and is also very important in Indo-China. No production statistics from South-East Asia are available, but it is a common market garden vegetable. It is regularly offered in the assortment of fresh vegetables sold by supermarkets in South-East Asian countries.

Properties

Per 100 g edible portion, tangho contains: water 90-94 g, protein 1.2-2.7 g, vitamin A 0.4-3.0 mg, vitamin B₁ 0.15 mg, vitamin B₂ 0.30 mg, vitamin C 17-45 mg, Ca 75 mg, Fe 2.7-4.2 mg. The weight of 1000 seeds is about 1.5 g.

Description

• An erect, densely leafy, branched, annual herb, 20-60 cm tall in the vegetative stage, up to ca. 90 cm when flowering.
• Leaves alternate, semi-amplexicaul, oblong to obovate in outline, 3-13 cm × 1-4 cm, variably incised from entire to 2-pinnatisect (most usual form) with oblong, lanceolate or linear, incise-dentate segments or lobes.
• Inflorescence a head, 3-6 cm in diameter; peduncle ribbed, 2-15 cm long; involucral bracts in 2-4 rows, margins scarious; ray flowers (marginal) 12-15, only female, ligule oblong, 1-1.5 cm × 5-8 mm, emarginate at apex, yellow; disk flowers (central) numerous, bisexual, with tubular corolla 4-5 mm long, yellow and 5-lobed at top.
• Fruit a glandular, more or less turbinate achene, 2-3 mm long, without pappus, in marginal flowers with 3 wings and 6-ribbed, in the central flowers with 1 wing and 10-ribbed.

Growth and development

The seed normally germinates within 10 days of sowing. Tangho flowers readily in temperate as well as tropical regions. It is basically a self-pollinated crop, but considerable cross-pollination may occur by insects or wind.

Other botanical information

Three types are usually distinguished based on the shape and the size of the leaves:

• small-leaf type: closest to the wild type with thin, finely divided, light green leaves and a strong taste; it is early-flowering, not strongly branched, and therefore low-yielding, but widely adapted to cool as well as warm climates;

• large-leaf type: with thick, shallowly lobed or entire, dark green leaves and a mild taste; the plants are larger, strongly branched, high-yielding and adapted to warm climates;

• intermediate type: with moderately thick and moderately indented, dark green leaves; the plants are strongly branched, fast-growing, high-yielding and adapted to both cool and warm climates; this is the most popular type.

This classification is gradually becoming obsolete as the distinctions are being eroded by breeding and selection, and instead named cultivars are becoming important. In Taiwan and southern China, a type occurs with obovate, thick, unlobed leaves called "Tiger Ear"; the leaves are tender and sweet and can be eaten raw like lettuce; it is not cold-resistant. There are special cultivars for ornamental use, which differ from the vegetable types in size and colour of the flowers.

Because of the enormous variability in leaf form, it becomes difficult to identify tangho always as C. coronarium. Typically C. coronarium has leaves that are 2-pinnatisect with linear lobes and the achenes of ligulate flowers bear an adaxial wing. It is possible that in the whole complex of tangho C. segetum L. (corn chrysanthemum) also is involved. This species is a rather common weed in Europe, northern Africa and western Asia, and its leaves are also edible. They are deeply incised-dentate, but never pinnatisect or linearly lobed and the achenes of its ligulate flowers are not adaxially winged.

Ecology

Tangho grows best in cool temperate climates, but it does well at higher elevations in the tropics. Some cultivars even tolerate light frost. Temperatures should not exceed 25 °C, as the crop will produce few leaves and will flower early.

Tangho seems to be photoperiod-insensitive, flowering readily at temperate and tropical latitudes. It grows relatively well at low light levels. It suffers from very wet conditions or heavy rainfall. Fertile, moisture-retentive soils are preferred, but tangho is not very demanding of soil type.

Agronomy

Normally tangho is propagated by seed, but like most chrysanthemums propagation by cuttings from older plants is also possible. Cuttings will root within a month. Seed of good quality can be stored for 2 years or longer. Seeds are small and should be sown shallowly and only lightly covered afterwards. They can be broadcast or sown in rows directly in the field, or sown in a seed-bed or tray and transplanted when 3-4 cm high. Plant spacing depends on harvesting stage (seedlings or mature plants) and harvesting method (pulling or repeated cuts) but varies from 5-15 cm × 5-15 cm. Tangho is sometimes cultivated in plastic tunnels or under shelters during the rainy season.

Seedlings can be harvested 4-5 weeks from sowing when they are 5-10 cm tall. They can be pulled, or cut several times over a period of about one month. Alternatively, plants are harvested when they are vegetatively mature (15-25 cm high at 6-8 weeks from sowing) and either pulled or harvested by repeated cuttings over a 3-month period.

The top of the main stem is sometimes pinched out to promote branching, and it is recommended to remove flower buds as they form, because they negatively affect vegetative growth and taste.

Tangho is suitable for intercropping because it is shade-tolerant. It is remarkably free from diseases and pests, and requires little care apart from weeding during early crop growth.

Like most leafy vegetables, tangho wilts rapidly after harvest. Refrigerated and wrapped in plastic, it stays fresh for two days.

In seed production, yields vary from 1300-2000 kg/ha.

Genetic resources and breeding

There seem to be no major germplasm collections apart from breeders' working collections. Selection work on tangho is mainly carried out in Japan. New cultivars adapted to a wide range of climates and to new cultivation methods (e.g. hydroculture), are being bred.

Prospects

Tangho is not a new crop in South-East Asia, but it has long been of minor importance as an ornamental or vegetable. The selection and commercialization of improved vegetable cultivars by Japanese and Taiwanese seed firms constitute a new impetus to its cultivation as a market garden vegetable.

Literature

• AVRDC, 1988b. Gardening nutritious vegetables. Asian Vegetable Research and Development Center (AVRDC), Shanhua, Tainan, Taiwan. 136 pp.
• Buishand, T., Houwing, H.P. & Jansen, K., 1986. Groenten uit alle windstreken [Vegetables from all corners of the world]. Spectrum, Utrecht, the Netherlands. p. 42.
• Chayamarit, K., 1984. Some medicinal plants of the family Compositae. Proceedings of the National Forestry Conference, November 19-23, 1984, Bangkok, Thailand. pp. 78-89.
• Herklots, G.A.C., 1972. Vegetables in South-East Asia. George Allen & Unwin, London, United Kingdom. pp. 168-171.
• Larkcom, J., 1991. Oriental vegetables. The complete guide for garden and kitchen. John Murray, London, United Kingdom. pp. 76-78, 136.
• Shinohara, S. (Editor), 1984. Vegetable seed production technology of Japan. Shinohara's Authorized Agricultural Consulting Engineer Office, Tokyo, Japan. Vol. 1. pp. 175-184.

Authors

• U.A. Dasuki & M.H. van den Bergh