Cosmos caudatus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Cosmos caudatus Kunth

Protologue: Nov. gen. sp. 4: 240 (1820).

Family: Compositae

Chromosome number: 2n= 48

Synonyms

• C. bipinnatus Ridley (1923), non Cavanilles (1791).

Vernacular names

• Cosmos (En)
• Indonesia: kenikir (Java), randa midang (West Java)
• Malaysia: ulam raja, pelampong
• Philippines: cosmos (Tagalog), turay-turay (Bisaya), onwad (Ifugao)
• Thailand: daoruang-phama (Bangkok), khamhae (northern).

Origin and geographic distribution

Cosmos is indigenous to tropical America. It was introduced by the Spaniards into the Philippines, possibly because it was used by them as a vegetable at sea. Now it is pantropical, including South-East Asia, where it is cultivated but also occurs in a naturalized state.

Uses

The leaves and young tops of cosmos are eaten as a vegetable in Indonesia and Malaysia, usually raw but also cooked and mixed with coconut sauce and chillies. The leaves have a very strong taste and smell of turpentine. Besides being used as a vegetable, cosmos is also grown for ornamental purposes; it occurs in many home gardens in Indonesia. In Malaysia it is used as a traditional medicine to purify the blood and to strengthen the bones. In the Philippines (Luzon) the leaves are reportedly used, mixed with rice, to prepare yeast. In early days cosmos was proposed as an auxiliary plant in agriculture, in particular to improve the soil structure and to suppress alang-alang (Imperata cylindrica (L.) Raeuschel).

Production and international trade

Cosmos is mainly cultivated for home consumption and marketed locally on a small scale. No production statistics are available.

Properties

Per 100 g edible portion, cosmos contains: water 93 g, protein 3 g, fat 0.4 g, carbohydrates 0.4 g, fibre 1.6 g, ash 1.6 g. Contents of Ca (270 mg) and vitamin A (0.9 mg) are high. The energy value is low, being 70 kJ/100 g edible leaves. The leaves also contain an essential oil.

Botany

• Annual to short-lived perennial herb, erect, in the upper half much branched, aromatic, up to 3 m tall.
• Stem longitudinally striate, green, often tinged with purple.
• Leaves opposite, 2-4 pinnate or pinnatipartite, triangular-ovate in outline, 2.5-20 cm × 1.5-20 cm, above dark green, subglabrous, below light green with minute hairs; petiole up to 5 cm long; ultimate leaf segments oblong-lanceolate, 0.5-5 cm × 1-8 mm.
• Inflorescence a head, terminal (with other heads forming a lax panicle) or axillary, solitary, in the axils of the higher leaves; peduncle 5-30 cm long; involucral bracts 8, linear-lanceolate, 1.5-2 cm long and reflexed in fruit; ray flowers 8, sterile, ligules linear-lanceolate, 1-1.5 cm × 0.5 cm, mostly violet or reddish, seldom yellow or white; tubular flowers bisexual, numerous, yellowish-green, 0.7-1 cm long.
• Fruit an achene, linear-fusiform, 4-angular, 1-3 cm long, black, ending in a beak with 2-3 short unequal awns.

C. caudatus can be easily confused with C. sulphureus Cav. because they look similar vegetatively and have some vernacular names in common (randa midang). They can be distinguished by the achenes: those of C. caudatus have conspicuous awns which are absent in C. sulphureus. The latter is more important as an ornamental, much less as a leafy vegetable.

Ecology

When not cultivated, cosmos often occurs as a weed in the neighbourhood of human habitations, e.g. in fields and waste places, from the lowlands up to 1600 m altitude. It likes sunny places with a not too humid atmosphere and a fertile and pervious soil.

Agronomy

Propagation is by seed. Sowing is done directly in the field or first in a nursery. The seedlings are transplanted to the field when they are three weeks old. Planting distances of 25-30 cm × 25-30 cm are recommended. On poor soils fertilizing with organic manure (10 t/ha) and urea (200 kg/ha) will increase the yield and improve leaf quality, as will good drainage in wet conditions and watering during dry periods. After 6 weeks the first leaves can be harvested and subsequent harvests can be every 3 weeks. Regular harvesting will stimulate production and delay flowering, and can continue until the plant is 2-3 years old. In humid conditions cosmos is often attacked by fungi (e.g. Sclerotium rolfsii ). Cosmos wilts easily and therefore should be marketed soon after harvesting.

Genetic resources and breeding

Selection, if any, has only been done by growers. A comparison of planting materials from home gardens and market gardens would provide some insight into the variation present.

Prospects

In some parts of South-East Asia, particularly in Indonesia and Malaysia, cosmos is a popular vegetable. In West Java it is becoming rather common in the assortment of fresh vegetables in supermarkets, which might give an impetus to new developments in this crop.

Literature

• 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 and Co., Amsterdam, the Netherlands. pp. 125-127.
• Soetomo Soedirdjoatmodjo, M.D., 1986. Bertanam sayur daun [Growing leafy vegetables]. Badan Penerbit Karya Bani, Jakarta, Indonesia. pp. 54-59.

Authors

• M.H. van den Bergh