Citrullus lanatus (Thunb.) Matsum. & Nakai

Cucurbitaceae

 
Author: Janine E. Victor (with additions from J. M. Suttie)
Synonyms

Colocynthus citrullus (L.) Kuntze
Cucurbita citrullus L.

Common names

Wild watermelon; tsamma; t'sama (Khoisan); karkoer; bitterwaatlemoen (Afrikaans); makataan (Tswana), watermelon.

  Taxonomy

Cucurbitaceae. There are three species in the genus Citrullus, occurring naturally in Africa and Asia.

  Origin and geographic distribution

The wild watermelon is widely distributed in Africa and Asia, but originates from southern Africa occurring naturally in South Africa, Namibia, Botswana, Zimbabwe, Mozambique, Zambia and Malawi. It is cultivated and adventive in warmer parts of the world. Watermelon is thought to have been domesticated at least 4,000 years ago, and the plant was grown as a crop in the Nile valley (Bates & Robinson 1995). The indigenous people of the Kalahari, in their search for water-containing foods, selected varieties with low glycoside content. From there followed the spread to the Mediterranean areas and in an eastern direction to India. Watermelons were developed as a crop in Egypt in ancient times and according to Encyclopaedia Britannica " The history of watermelons is a long one; there is a Sanskrit word for watermelon, and fruits are depicted by early Egyptian artists, indicating an antiquity in agriculture of more than 4,000 years". Purseglove ( 1968) indicates that it is of ancient cultivation in the Mediterranean and reached India in prehistoric times, but did not reach China until the eleventh century AD. Some websites suggest an introduction to India in 800 AD. C. lanatus var. fistulosus, the "tinda", which has small, apple sized fruit, is grown as a vegetable in India. Modern day cultivated varieties are a popular crop that can be cultivated in any climate that has warm summer, and are best suited to those climates that have long hot summers.

  Description (Jeffrey 1978)

An annual herb with long (up to 10 m) stems lying or creeping on the ground, with curly tendrils. Leaves are 5-20 by 3-19 cm, and hairy, usually deeply palmate with 3-5 lobes, on 2-19 cm long petioles. Male flowers on 12-45 mm long pedicels. Flowers 1-2.5 cm long, pale green. Flowers monoecious, solitary, on pedicels up to 45 mm long; with 5 shortly united petals, pale green. Fruit of wild plants 1.5-20 cm in diameter, subglobose, greenish, mottled with darker green; of cultivated plants up to 30x60 cm, subglobose or ellipsoid, green or yellowish, evenly coloured or variously mottled or striped. Fruits vary considerably in morphology. Whereas the fruits of the wild Kalahari form are small and round, the cultivated forms are large oblong fruits. In addition, they vary from pale yellow or light green (wild form) to dark green (cultivars), and with or without stripes; the pulp varies from yellow or green (wild forms) to dark red (cultivars).

  Use

Tsamma fruits are the important source of water in the Kalahari during dry months of the year when no surface water is available. The fruit is cut open at the one end and the first piece of flesh is eaten. The content is pounded with a stick, and this is then eaten and drunk. Seeds are roasted and ground into tsamma meal, a nutritious food with a pleasant nutty taste. Leaves and young fruits are utilised as green vegetables (Van Wyk & Gericke 2000). The peels of the fruit are traditionally used for making jam. In the Kalahari, the fresh tsamma fruits are used as a stock feed in times of drought (Van Wyk & Gericke, 2000). The cultivated watermelon is a popular summer fruit in all parts of the world.

  Phytochemistry

The fresh fruit contains cucurbitacins that burn the mouth.

  Toxicity

Unknown

  Ecology

In its natural environment, Citrullus lanatus grows in grassland or bushland, often along watercourses, at altitudes of 50 to 1400m.

  Growth requirements

Citrullus lanatus grows on well drained soil and seeds require soil temperatures of 70-95 0F to germinate. Root growth is impeded by compacted soil. Citrullus lanatus withstands drought better than most melons.

  Links

Commercial Watermelon Production

Watermelon (Food Resource)

Watermelon Breeding

Citrullus lanatus Water Melon (by Dr. Wolfgang Schuchert)

Iziko Museums of Cape Town

  References

Bates, D.M. & Robinson, R.W. 1995. Cucumbers, melons and water-melons. In Smartt, J. & Simmonds, N.W. (eds), Evolution of Crop Plants. Longman, London.

Jeffrey, C. 1978. Cucurbitaceae. Flora Zambesiaca 4: 433-434. Purseglove, J. G. (1968) Tropical Crops Dicotyledons Longmans, London

Van Wyk, B.-E. & Gericke, N. 2000. People's plants. Briza, Pretoria.