Euryale ferox, commonly known as prickly waterlily,[3] makhana, or Gorgon plant, is a species of water lily found in southern and eastern Asia, and the only extant member of the genus Euryale. The edible seeds, called fox nuts or makhana, are dried,[a] and eaten predominantly in Asia.
The genus is named after a mythical Greek Gorgon, Euryale.[9] The specific epithet ferox means fierce or ferocious.[10]
Distribution
Euryaleferox is a perennial plant native to a range from northern India to Taiwan and far eastern Russia.[11]
Recently, E. ferox has been recorded in Serbia, Europe. It was probably dispersed to Serbia through migrating birds.[12]
Description
Euryale ferox grows in fresh water ponds, producing flowers with white inner petals and violet outer petals. The leaves are large, round and peltate, often more than a meter (3 feet) across, with a leaf stalk attached in the centre of the lower surface. The leaves are deep green; the leaf veins are purplish. The stems and leaves are covered in sharp prickles. It can be grown in shallow water or rich soil. It does not tolerate shade or cold.[13][14]
Surface-floating leaf of Euryale ferox
Euryale ferox Salisb. seedling with scale bar (3 cm) on a white background
A pond of cultivated Euryale in northern India
Reproduction and genomics
Self pollination can occur. Pollen is released before the flower opens.[15] The majority of Euryale ferox flowers are cleistogamous, not opening for cross-pollination, though some normally-opening (chasmogamous) flowers do occur.[16]
The chromosome count is n = 29. The genome size is 870.42 Mb.[17] The chloroplast genome is 159930 bp long.[18]
Cultivation
Fox nuts have traditionally been harvested by diving without breathing equipment to a depth of 8 feet (2.4 m) in freshwater ponds. This is arduous, with skin hazards from mud and the plant's thorns. In the 21st century, the National Research Centre for Makhana has pioneered the plant's cultivation in fields flooded to a depth of 1 foot (0.30 m) which makes production and harvesting easier. The area of land devoted to fox nut production has increased to 87,000 acres (35,000 ha) by 2022. The centre has developed a more productive variety, increasing farm income, and is designing a harvesting machine.[19]
Uses
Makhana being lightly roasted, ready to eat
The seeds[20] and petioles are used as food.[21] The plant is cultivated for its seeds[22] in lowland ponds in India, China, and Japan. The Chinese have cultivated the plant for centuries.[23] In India, more than 96,000 hectares of Bihar, where it is called Mithila Makhana, were set aside for cultivation of Euryale in 1990–1991.[9] Bihar produces 90% of the world's fox nuts.[22] In the northern and western parts of India, Euryale ferox seeds are often roasted or fried, which causes them to pop like popcorn.[24] These are then eaten, often with a sprinkling of oil and spices. They are also used in other types of cooking, especially to make a porridge or pudding called kheer.[14] The seeds are used in Cantonese soup,[25] in Ayurveda preparations, and in traditional Chinese medicine.[22]
Evidence from archaeobotany indicates that Euryale ferox was a frequently collected wild food source during the Neolithic period in the Yangtze region, with many finds from the sites of Kuahuqiao, Hemudu, and Tianluoshan.[26] The earliest recorded use of E. feroxis from Gesher Benot Ya'aqov, Israel, among artifacts of the Acheulean culture 750–790,000 years ago.[20]
Conservation status
The species is classified on the Red List of endangered plants in Japan and given the designation "vulnerable".[16][27] It is classified as species of Least Concern (LC) by the IUCN Red List of Threatened Species.[1] However, a population decline on the global scale has been reported.[16] It is classified as vulnerable (VU) in South Korea.[28]
