Kollut poisonings: How a Philippine tribe fought back against the Japanese during World War II

Kollut (Dioscorea hispida), the wild root crop that can cause paralysis. (Boonchuay1970/Shutterstock)

There’s a plant indigenous to Mindanao called kollut, also known as kayos, korot or nami. Kollut (Dioscorea hispida) is a wild root crop that is historically known as a famine food. Filipino natives only ate kollut during tough times, and only after a special process of preparation because before this root crop can be edible, kollut is incredibly poisonous, hence its other name, ‘poisonous yam.'

The Japanese and the Monuvu

World War II was a historic and cruel event involving millions of people from different countries in the fight for superiority. This global war was especially hard on the Philippines since it was an American colony at the time. Right after the bombing of Pearl Harbor, the Japanese invaded the country and were merciless to Filipinos. 

There are many stories of the brutality of the Japanese. Despite being in far-flung areas, even indigenous tribes could not escape their cruelty. The Monuvu, a tribe residing in central Mindanao, were said to have been forced into labor and often had their food stolen as they travelled. 

Japanese soldiers had the advantage of numbers and weaponry, but this did not mean the Monuvu people did not fight back. Datu Lamberto Delfin of Mua-an, a tribal leader, told a story of how the Monuvu took advantage of the Japanese’s barbarity. Since the Japanese often stole the sweet potatoes the tribe carried as they travelled, the Monuvu brought kollut instead, and let the Japanese ‘steal’ them. 

Kollut is a poisonous yam that can only be edible after a series of processes which removes the poison. The preparation involves soaking or washing its slices under running water for several days, drying it under the sun, and burying it in ash for up to a week. Without this process, kollut had a potent dose of poison that can induce paralysis and sickness.

Of course, the Japanese were unaware of this lengthy detoxifying process and ate  kollut as is. Sure enough, the Japanese soldiers collapsed. As soon as they became unable to move, the Monuvu took up arms and attacked to defend themselves.

Effects as a wild crop

Kollut is a twining vine, arising from tuberous roots and reaching a length of several meters. It is not only native to the Philippines, but it can also be found and is eaten in other Asian countries such as Thailand and India.

The Monuvu knew that kollut could cause paralysis, but other sources say that it also induces sleep or intoxication. When eaten in small amounts, it is said to be intoxicating with a similar effect to beer, which is why it is also called “intoxicating yam.” However, eating it in larger portions may cause death, as it was said to have also been used for executing criminals and to create poison arrows.

With the right preparation, kollut can still be eaten safely. A study by the University of Eastern Philippines found that kollut is rich in carbohydrates and can be a substitute for rice. 

The Philippines had gone through hardships due to the cruelty of the Japanese, but it did not mean that Filipinos simply endured. The Monuvu ‘s story about kollut is a clear symbol of the Filipinos’ resistance and desire for freedom.

Historical information has been sourced from the Siliman Journal of Siliman University.