Ipomoea aquatica

 

Ipomoea aquatica is a semiaquatic, tropical plant grown as a leaf vegetable. It is found throughout the tropical and subtropical regions of the world, although it is not known where it originated. This plant is known in English as water spinach, river spinach, [1] water morning glory, water convolvulus, or by the more ambiguous names "Chinese spinach", "Swamp cabbage" and "Kangkong" in Asia. [2] Occasionally, it has also been mistakenly called "kale" in English, although kale is a different plant belonging to the Brassica oleracea Acephala Group and completely unrelated to water spinach. It is known as phak bung in Thai, trokuon in Khmer and kangkung in Malay and Indonesian. In the Philippines a variety of Kangkong is grown in canals dug by the Americans during the occupation after the Spanish American war. Another variety in the Philippines that grows on land is called "Chinese Kangkong" in the Philippines as opposed to the variety that is grown in water that is simply called Kangkong or "native" Kangkong.

I. aquatica grows in water or on moist soil. Its stems are 2–3 metres (7–10 ft) or more long, rooting at the nodes, and they are hollow and can float. The leaves vary from typically sagittate (arrow head-shaped) to lanceolate, 5–15 centimetres (2–6 in) long and 2–8 centimetres (0.8–3 in) broad. The flowers are trumpet-shaped, 3–5 centimetres (1–2 in) diameter, usually white in colour with a mauve centre. The flowers can form seed pods which can be used for planting.[3]

 

 

Cultivation　　

 

Ipomoea aquatica is most commonly grown in East and Southeast Asia. Because it flourishes naturally in waterways and requires little, if any, care, it is used extensively in Thai, Lao, Cambodian, Malay, Vietnamese and Chinese cuisine, especially in rural or kampung (village) areas.

The vegetable is also extremely popular in Taiwan, where it grows well. During the Japanese Occupation of Singapore in World War II, the vegetable grew remarkably easily in many areas, and became a popular wartime crop.

It has also been introduced to the United States, where its high growth rate has caused it to become an environmental problem, especially in Florida and Texas. It has been officially designated by the USDA as a "noxious weed"[4] (the term "noxious" refers to its effect on the environment, not to any toxicity).

The plant when eaten raw may transmit Fasciolopsis buski, an intestinal fluke parasite of humans and pigs, causing

 

 

 

Culinary uses

 

The vegetable is a common ingredient in Southeast Asian dishes. In Singapore, Indonesia and Malaysia, the leaves are usually stir-fried with chile pepper, garlic, ginger, dried shrimp paste (belacan/terasi) and other spices. In Penang and Ipoh, it is cooked with cuttlefish and a sweet and spicy sauce.

Chinese cuisine (Chinese: 空心菜; pinyin: kōngxīncài; literally "hollow vegetable") has numerous ways of preparation, but a simple and quick stir-fry, either plain or with minced garlic, is probably the most common. In Cantonese, the water spinach is known as 蕹菜 (Jyutping: ung3 coi3, sometimes transliterated as ong choy). In Cantonese cuisine, a popular variation adds fermented bean curd. In Hakka cuisine, yellow bean paste is added, sometimes along with fried shallots.

In Thailand, where it is called phak bung (Thai: ผักบุ้ง), it is eaten raw, often along with green papaya salad or nam phrik, in stir-fries and in and curries such as kaeng som.[6]

In Laos, where it is known as pak bong (ຜັກບົ້ງ), and in Burma, where it is called ga zun ywet, it is frequently stir-fried with oyster sauce or yellow soybean paste, and garlic and chillies.

In Vietnam, I. aquatica (known as rau muống) once served as a staple vegetable of the poor. In the south, the stems are julienned into thin strips and eaten with many kinds of noodles. It is used as a garnish, as well. It has become a common ingredient of Vietnamese cuisine.

In the Philippines, kangkóng is usually sautéed in cooking oil, onions, garlic, vinegar, and soy sauce. This dish is called adobong kangkong. It is also a common leaf vegetable in fish and meat stews, such as sinigang. An appetizer in the Philippines, called crispy kangkong, uses the leaves coated with batter and fried until crisp and golden brown.[7]

In South India, the leaves are finely chopped and mixed with grated coconut to prepare thoran (തോരന്‍), a Keralan dish.

In Bangladesh and West Bengal, it is known as kolmishak (কলমীশাক) and stir-fried preparation of the leaves is a very popular dish.[8]

In Kuching, Hokkien Dielect called it Eng Cai. It is usually fried with fermented krill "belacan eng cai", boiled with preserved cuttlefish then rinsed and mix with spicy rojak paste "jiu hu eng cai"[9], boiled eng cai also used to serve with fermented krill noodle "belacan bee hoon" and prawn noodle [10]