Citrullus colocynthis

alt=Citrullus Colocynthis Fruit in Behbahan|thumb|Citrullus Colocynthis Fruit in [[Behbahan]]

alt=Wild Citrullus Colocynthis in Behbahan|thumb|Wild Citrullus Colocynthis

Citrullus colocynthis, with many common names including colocynth, bitter apple, bitter cucumber, vine of Sodom, or wild gourd, is a poisonous desert viny plant native to the Mediterranean Basin and West Asia, especially the Levant, Turkey (especially in regions such as İzmir), and Nubia.

It resembles a common watermelon vine but bears small, hard fruits with a bitter pulp. The plant contains cytotoxic cucurbitacins and is thus unsafe to use as an herbal medicine. It originally bore the scientific name Colocynthis citrullus.

Description

The vine ranges from in length.

Roots and stems

The roots are large, fleshy, and perennial, leading to a high survival rate due to the long tap root. The vine-like stems spread in all directions for a few meters looking for something over which to climb. If present, shrubs and herbs are preferred and climbed by means of auxiliary branching tendrils.

Leaves

Very similar to watermelon, the leaves are palmate and angular with three to seven divided lobes.

Flowers

The flowers are yellow and solitary in the axes of leaves and are borne by yellow-greenish peduncles. Each has a subcampanulated five-lobed corolla and a five-parted calyx. They are monoecious, so the male (stamens) and the female reproductive parts (pistils and ovary) are borne in different flowers on the same plant.

The male flowers' calyx is shorter than the corolla. They have five stamens, four of which are coupled and one is single with monadelphous anther. The female flowers have three staminoids and a three-carpel ovary. The two sexes are distinguishable by observing the globular and hairy inferior ovary of the female flowers.

Seeds

The seeds are gray and long by wide.

They are similarly bitter, nutty-flavored, and rich in fat and protein. They are eaten whole or used as an oilseed. The oil content of the seeds is 17–19% (w/w), consisting of 67–73% linoleic acid, 10–16% oleic acid, 5–8% stearic acid, and 9–12% palmitic acid. The oil yield is about 400 L/hectare. In addition, the seeds contain a high amount of arginine, tryptophan, and the sulfur-containing amino acids.

Similar species

It resembles the watermelon, which is in the same genus.

Distribution and habitat

thumb|upright=1.3|Colocynths in [[Adrar Region|Adrar Desert (Mauritania)]]

Citrullus colocynthis is a desert viney plant that grows in sandy, arid soils. It is native to the Mediterranean Basin and Asia, and is distributed among the west coast of northern Africa, eastward through the Sahara, Egypt until India, and reaches also the north coast of the Mediterranean and the Caspian Seas. It grows also in Southern Europe and on the Aegean Islands. On the island of Cyprus, it is cultivated on a small scale; it has been an income source since the 14th century and is still exported today.

It is an annual or a perennial plant in the wild in Indian arid zones, and survives under extreme xeric conditions. To enhance production, an organic fertilizer can be applied.

Colocynth is also commonly cultivated together with cassava (intercropping) in Nigeria.

Cultivated colocynth suffers of climatic stress and diseases such as cucumber mosaic virus, melon mosaic virus, Fusarium wilt, etc. as any other crop. To improve it, a relatively new protocol for regeneration has been developed with the aim of incorporating disease and stress resistance to increase yield potential and security avoiding interspecific hybridization barriers.

Uses

thumb|Iranian fruit

C. colocynthis can be eaten or processed as energy source, e.g. oilseed and biofuel.

The characteristic small seed of the colocynth have been found in several early archeological sites in northern Africa and the Near East, specifically at Neolithic Armant, Nagada in Egypt; at sites dating from 3800 BC to Roman times in Libya; and the pre-pottery Neolithic levels of the Nahal Hemar caves in Israel. Zohary and Hopf speculate, "these finds indicate that the wild colocynth was very probably used by humans prior to its domestication." The powder of colocynth was sometimes used externally with aloes, unguents, or bandages. Lozenges or pastilles made of colocynth were called "troches of alhandal" or trochisci alhandalæ and used as a laxative. The desert Bedouin are said to make a type of bread from the ground seeds. The closely related watermelon (Citrullus lanatus (Thunb)) was domesticated in Ancient Egypt, and may have been developed for edible seed from cultivated colocynth.

In West Africa, the seeds of the colocynth (called egusi) are used as the basis for making egusi soup.

The flowers can be eaten, and the stem tips are a source of water.

Oleic and linoleic acids isolated from C. colocynthis petroleum ether extracts show larvicidal activity against mosquitoes.

References

External links

Information on oilseed uses