This plant is highly favored in South Korea, China, and Japan.
A Plant with a Scary Name
In the plant kingdom, there exists a species with a frightening name that is actually beloved in many Asian countries. This plant is known in English as “Devil’s tongue.” The name comes from the unique shape of its flower, which resembles a leaf emerging from a trumpet. This plant is konjac (Amorphophallus konjac).
Konjac is a plant favored in many Asian countries. (Photo: An ninh Thủ đô).
According to An ninh Thủ đô, konjac (Amorphophallus konjac) is a fascinating perennial plant. It belongs to the Araceae family and grows from a large bulb that can reach up to 25 cm in diameter.
Illustration of the konjac plant in Curtis’s Botanical Magazine. (Photo: Curtis’s Botanical Magazine).
The book “Medicinal Plants and Herbs of Vietnam” by Đỗ Tất Lợi states that konjac is a perennial plant with a large, flattened bulb that can be larger than an adult’s head, with yellow flesh that has a slightly irritating texture. The leaves are simple, with petioles reaching up to 40 cm or more, dark green with white spots, divided into three long segments of around 50 cm, and the leaf blades are deeply lobed. The inflorescence ends with a sterile part, cylindrical in shape, and purple in color. The spadix is dark brown, and the flowering season is in summer and autumn.
Leaves grow directly from the bulb, and after flowering, typically only one leaf remains. Each leaf is divided into three smaller branches, which further branch out. The leaf blade is dark green with white spots, often deeply lobed into feather-like segments, and can reach a width of 1.3 meters. The thick petiole is also known as “Dọc nưa.”
Each inflorescence of konjac can reach up to 1.5 meters in length. (Photo: An ninh Thủ đô)
Information from An ninh Thủ đô indicates that the inflorescence grows on a long petiole and stands upright. Each inflorescence can reach up to 1.5 meters, making konjac one of the largest flowering plants in the world. It has a large spathe with wavy edges, dark purple on the inside and green on the outside. Surrounding this spathe is a long stalk that is twice the length of the spathe, containing female flowers below and male flowers above. The flowers are unprotected, with male flowers having separate stamens and female flowers having an egg-shaped ovary.
Similar to the corpse flower, the konjac flower emits a smell reminiscent of rotting flesh. This odor attracts flies for pollination. It’s not surprising since konjac is a close relative of the corpse flower (Amorphophallus titanum), known for having the largest unbranched flower cluster in the world.
The fruit of the plant is a type of berry.
Konjac grows wild across the mountainous provinces of Vietnam. (Photo: An ninh Thủ đô)
This plant is distributed in warm climate regions of East Asia and Southeast Asia, including Vietnam. Konjac grows wild throughout the mountainous provinces of Vietnam, thriving in dry areas, often found under the canopy of forests. It is currently primarily found in the northern and central mountainous provinces such as Hòa Bình, Điện Biên, Yên Bái, Lai Châu, Lào Cai, Bắc Giang, Nghệ An, Hà Tĩnh, Thừa Thiên Huế, and more.
A Plant Popular in Many Countries
Originally a wild plant, konjac has been cultivated in many locations, especially in China, Japan, and South Korea, for harvesting its starchy bulbs as food.
The book “Medicinal Plants and Herbs of Vietnam” mentions that konjac is grown for its edible bulbs. The bulbs should be harvested early when they are not fully matured, as they are typically softer and less irritating at this stage. After harvesting, the bulbs are peeled, cooked, and either dried or sun-dried. When ready to use, they must be soaked until soft, sliced thinly, and soaked in alum water and ginger to eliminate any irritation. To be edible, the bulbs need to be processed with lime to remove their irritating properties.
In Japan, konjac is known as “konnyaku” (which is the source of the name “konjac” in English) and plays a significant role in Japanese cuisine, commonly used in dishes like oden, noodle making, and jelly. Historians have found a cookbook titled “100 Delicious Dishes with Konjac” published in 1864.
This plant is cultivated for its edible bulbs. (Photo: An ninh Thủ đô)
Konjac is not only an ingredient in cuisine but also a medicinal herb commonly used in traditional Eastern medicine. This plant has a long history in traditional medicine, documented in many valuable medical texts such as “Bản thảo cương mục,” “Lôi hổ ký,” and others.
In Western medicine, konjac consists of up to 97% water, with the remaining 3% being glucomannan fiber – an important component that helps with intestinal cleansing and motility. Therefore, the Japanese often use konjac as a health food.
The Japanese often use konjac as a health food. (Photo: You Med)
For example, shirataki noodles made from konjac are very low in calories (only about 5 calories per 100 grams), low in carbohydrates, gluten-free, and completely vegan. Shirataki noodles and other dishes made from konjac can help control blood sugar levels, lower cholesterol, and are friendly for diabetic and cardiovascular patients.
However, experts warn that konjac bulbs can be toxic, so it’s essential to exercise caution when using konjac-based remedies and to consult a doctor to avoid any unwanted effects.
The Economic Value of Konjac
Konjac is an economically significant crop (with the price of 1 ton of konjac flour reaching around $13,000 to $15,000) widely used in food, medicine, and the chemical industry in many countries around the world.
In Vietnam, konjac is a traditional crop maintained by many localities through generations. It is primarily cultivated from Nghệ An to Thừa Thiên-Huế province. Notably, konjac is considered a “specialty” of Đông Sơn village, Hải Sơn commune, Hải Lăng district (Quảng Trị province). Here, every part of the konjac plant is utilized. During harvest, leaves are given to pigs, and while large bulbs are selected for seeds, the rest are used as food or sold to confectionery producers.
Konjac is an economic crop in many localities in Vietnam. (Photo: An ninh Thủ đô)
In an interview with Quảng Trị newspaper, Lê Thanh Thắng, the leader of Đông Sơn cooperative, shared that there are about 10 households currently growing konjac specialty in the village, with a total area of nearly 1 hectare. Most households utilize their one-crop rice fields to grow konjac to increase income. If there is a stable market with larger quantities, the local people will expand their cultivation area.
For konjac grown in An Giang province, the flour obtained from this plant (locally known as “củ huyền”) is used for drinks, cakes, and noodles. In Trà Vinh province, many locals have planted konjac alongside sugarcane and rice to boost their income. Many young people are utilizing products made from konjac in conjunction with experiential tourism and culinary ventures to launch their startups.
- A sweet, refreshing bulb comparable to ginseng, readily available in Vietnam
- A bulb many people dismiss as ‘bland’ turns out to be a ‘medicine’ for boosting immunity and cancer prevention at a low cost
- A dried bulb known as the “longevity medicine” that helps nourish the kidneys and effectively controls blood sugar
