Sawah Lettuce, Sawah Flowering Rush
Limnocharis flava

Family: Alismataceae

What it is like

Sawah lettuce (Limnocharis flava), also known as yellow sawah lettuve, yellow burr head, or yellow velvetleaf, is an aquatic flowering, clump-forming, perennial plant which produces erect stems about 20-40cm tall from a short thick rhizome. It is native to Dominican Republic, Mexico, Haiti, Cuba, South America, and Central America but widely naturalized in southern and southeastern Asia. The triangular leaves form into clumps. The stems are hollow. The inflorescence consists of three-lobed yellow flowers. The fruits are spherical. Though considered as an invasive plant and has great potential to become a weed, it is a known vegetable in some countries. In particular, the flower stalk and leaves are used in dishes as well as the immature flower buds. The plant is also used for green manure.

Limnocharis flava is an evergreen Perennial growing to 0.6 m (2ft) by 0.6 m (2ft in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid and neutral soils and can grow in very acid soils. It cannot grow in the shade. It prefers moist or wet soil and can grow in water.

Height (m): 0.6

Where it is found

In or at the edge of water. Shallow swamps, ditches, pools and wet rice fields, occurring usually in stagnant fresh water.

Southern S. America - Argentina, Paraguay, north through Central America to Mexico.

Conservation Status: This taxon has not yet been assessed

Countries/locations it is found in

Argentina, Asia, Bolivia, Brazil, Cambodia, Central America, China, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, Grenada, Haiti, Hawaii, India, Indochina, Indonesia, Laos, Malaysia, Mexico*, Nicaragua, North America, Pacific, Panama, Paraguay, Peru, SE Asia, South America, Thailand, USA, Venezuela, Vietnam,

How it is used

Food

Rating: 4

Leaves, leaf stems, flower stalks and young inflorescences are eaten cooked. They can be steamed like endive or spinach, added to soups or mixed with other vegetables. The young leaves and tops of the plant are boiled or cooked in mixed soups. The vegetable contains relatively high levels of Calcium, Iron and vitamin A, which are nutrients that are frequently insufficient in the diets of women in low-income countries.

Medicine

Rating: 0

Other

Rating: 2

Agroforestry Uses: The plants are sometimes used for green manure. Other Uses None known

Green manure: Fast-growing plants that can be used to increase the fertility of the soil.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

Grows best in shallow, neutral to slightly acidic water. If allowed to grow unchecked, the plant may become a very invasive environmental weed of streams and wetlands. It has become a serious weed in rice fields, irrigation canals and wetlands in South-East Asia. Clumps of the weed provide a congenial breeding site for disease-vectors, including mosquitoes, which encourages the spread of diseases such as Japan fever and dengue fever. Plants are reproduced mainly by seeds - these are dispersed via the production of fruitlets, which are buoyant and carried by water to new localities, dispersing seeds along the way. Fruiting takes place throughout the year, with a single fruit producing about 1,000 seeds and a single plant producing about 1,000 fruits per year. Bloom Color: Bright Yellow White/Near White. Spacing: 18-24 in. (45-60 cm).

Propagating it: Seed - seed must be kept damp or it loses viability. Sow in a constantly damp medium at 20c, cover with silver sand and immerse in 1cm of water once the seedlings have germinated. Division

Best place to grow:

Habit: Perennial

Hardiness: 10-12

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Moist, wet, water

Things to keep in mind

Its other names

Local names

Sawah Lettuce, Sawah Flowering Rush, Bak kanjong, Bengok, Berek, Bon cheen, Etjeng, Genjur, Jinjir, Keo neo, Ne thao, Phak kanjong, Phak pai, Sawah-flower rush, Sawah-lettuce, Talapat Rusee, Trakiet paong, Velvetleaf, Yellow burhead,

Synonyms

Alisma flavum L. Damasonium flavum Mill. Limnocharis emarginata Humb. & Bonpl. Limnocharis laforesti