Since early historical times, the sweet potato (botanical name: Ipomea batatas) has been a humble food of the masses. During the early period of Indian history, Rama, the dark-skinned prince of Ayodhya, went to live in the forest for fourteen years with his wife Sita and brother Laxmana, only to fulfil a promise made by his father Dasharatha to his wife (Rama’s step mother Kaikei). In the forest, Rama and his companions had to eat roots and tubers like sweet potatoes as well as wild fruits. Sweet potato is a common root that can be eaten both raw and cooked.

According to legend, the Portuguese brought sweet potato (see, Manjunath) to India five centuries ago, along with chilies, beans, potato, cassava, breadfruit, sunflower, groundnut, pineapple, guava, sapota, passion fruit, cashew, tobacco, onion, garlic, and other foods. Sweet potato is said to have been present on the American continents for 5000 years. Archeological evidence suggests that it was cultivated in South America around 2400 BC, and Columbus is said to have discovered it in the Caribbean region around 1502.

Balasubramanian, a reader who commented on Manjunath’s cited post on imported vegetables, elucidated an interesting custom of Tamil Brahmins using native vegetables and materials in shraddha ceremonies. Sweet potatoes are one of the acceptable tubers used in the preparation of ceremonial food, indicating that they have been native to our land for a long time. Bitter gourd, raw bananas, banana stem, colocasia, snake gourd, cluster beans, local cucumber, sweet potato, ginger, raw mango, and black pepper are among the ingredients. Similarly, on the uttarakriya day, Tulu households use specific vegetables and other materials for meal preparation.Raw bananas, ash gourds, and the inner part of the plantain (banana) stem are the essential vegetables for obituary ceremonies in Tulu families, though modernization has tacitly replaced some of the traditionally accepted items in the menu with currently popular ‘desi’ items (like chillies for black pepper). These obituary traditions appear to be quite ancient, and more research into the nature and evolution of our traditional ceremonies is desirable.
Balasubramanian differentiates between ‘valli kizhangu’ (sweet potato) and’mara kizhangu’ (cassava). Cassava (tapioca) is also known as’mara kireng’ in Tulu, where’mara’ (= tree) refers to the cassava shrub. The Tamil word sarkarai valli kizhangu, on the other hand, is a clear translation of sweet ‘vine tuber’ inspired by the imported name sweet potato.

Aside from its emphasised nativity to the American continents, the sweet potato is grown in a variety of places, including Polynesia, New Zealand, and China. It is known as ‘Kumara’ in Polynesia, New Zealand, and Peru. The similarity between Kumara and the Sanskrit word may be coincidental. However, linguistics such as Michael Witzel believe that the word ‘Kumara’ in the Rigveda, written in Indo-Aryan (early Sanskrit), is an extraneous word borrowed from an unknown language. It is still unknown how the sweet potato spread to different continents.

The sweet potato’s Tulu and Tamil names are intriguing. In Tulu, it is spelled ‘kireng’ (also spelled ‘kileng’ and other variants), and in Tamil, it is spelled ‘kilang’ (or with slightly different but allied pronunciation like kizhangu). Both words have the same meaning: keeL or keer = lower or underground; ang=part. The nomenclature is entirely unique and not based on the imported name of sweet potato. The names of the majority of imported vegetables and fruits are similar to or derived from their foreign names. The Malayalam word ‘kiraNNu’ is related to words in Tulu and Tamil. However, the sweet potato is known as ‘genasu’ in Kannada and Telugu.Apart from the kempu kireng (=red sweet potato), boldu kireng (=white sweet potato), and mara kireng (=cassava), Tulu Nighantu (=dictionary) mentions several related species of sweet potatoes, including: Tuppe kireng, koLLi kireng, guddoli kireng, toonNa kireng, pottel kireng, muLLu kireng. I’ve seen tuppe kireng, a short tuber variety named after tuppa, the butter. MuLLu (=spines) kireng is a kireng with spines. Other species may still exist in our rural areas, and our botanists should investigate these research possibilities. The Portuguese could not have brought all of these tubers, some of which were rare and vanishing species. Tribals in India continue to eat a variety of tubers. Many of these tubers may have been present on our land for millennia.

The similarity of Tulu and Tamil words for sweet potato (or related tuber) suggests that the tuber is ancient. The borrowing of Tulu/Tamil words in the Rigveda suggests that proto-Tulu and proto-Tamil tribes coexisted in early Vedic times (ca. 1500 to 500BC). (Please see previous postings, No.26.) The mention of edible tubers in the Ramayana (circa 500-200 BC) only adds to this theory.

Other agricultural crops face similar challenges. For example, peanut (groundnut) is also considered an American native, but it has been cultivated in China since 1500 BC. The antiquity of agricultural crops suggests that many of them are at least as old as our civilization. For example, how can the nativity of a now-ubiquitous plant like coconut be improved? Coconut (Cocos nucifera) has been found on Earth since the Miocene epoch, approximately 20 million years ago, i.e. long before man appeared on this planet.

The nativity of sweet potatoes and other agricultural crops in South America has been asserted based on extensive archaeological and paleobotanical studies conducted in the Americas. Similar studies in the Indian context would be extremely beneficial for a better understanding of our past.