Water hyacinth can be eaten, scholar insists
The prime minister’s rebuke to critics of his water hyacinth removal mission has stirred online debate on the edibility of the floating perennial plant.
Since early this month, getting rid of water hyacinth from natural waterways has become one of Prime Minister Prayut Chan-o-cha’s priorities in a campaign to lessen the scale of flooding.
This invasive plant species, called phak top chawa in Thai, quickly reproduces and doubles in numbers within just two weeks. As a result, it usually forms dense, impenetrable mats over vast areas of canals, rivers and ponds, blocking waterways.
On the orders of Gen Prayut, the Marine Department has removed about 55,000 tonnes of the plants from a stretch of the Chao Phraya River in Chai Nat.
The premier hailed the operation as a success and urged other state agencies to do the same so floodwater can be quickly drained during the wet season.
Some, however, came out to question whether such micro-management should be a priority of the premier’s job. In his response on Friday, Gen Prayut brushed off the criticism and defied his critics to cook the plants and eat them, just as they might eat morning glory or phak boong.
His remark prompted Chulalongkorn University academic Jessada Denduangboripant to clarify on his Facebook that the plant is actually edible.
“Phak top chawa can be cooked as part of a curry. It is a local menu item,” he said.
In his post, he shared a number of water hyacinth-based recipes. Local people who live along ponds pick baby leaves and stalks of water hyacinths and cook them with catfish meat in a curry, he said.
Baby leaves can also be steamed for eating with chilli paste, he added.
In response, netizens agree, saying they eat the weed and have shared their recipes, he said.
One Facebook user questioned his suggestion saying the aquatic plant is used to help in wastewater treatment due to its ability to absorb toxic metal substances, so it is not safe to eat.
Another said the it is safe as long as it is collected from clean water sources.
He said he was concerned about water hyacinths which migrate a long way through inter-provincial rivers, such as the Chao Phraya, passing places where toxic substances are released such as factories.
“I wonder whether he just wanted to criticise the prime minister,” he said, adding the lecturer’s recommendation could put people’s health at risk.
Mr Jessada has responded, saying he did not suggest anyone eat the plant if they collect it from wastewater treatment sites or polluted sources.
It is true the plant can absorb metal substances and has been used to treat wastewater, he said.
But a study by Khon Kaen University indicates that water hyacinths collected from some natural water sources in the Northeast contain a very low level of metal substances or are barely contaminated with toxic elements. Toxic substances were only found at low levels in the roots of the plant, not edible leaves or stalks, he said.