Taro

• 1. Introduction

  ›

  Taro, the root vegetable that botanists call Colocasia esculenta, reached 18 million tonnes of world production in 2022. Nigeria alone grew 46 percent of that total, far ahead of every other country. The crop ranks fifth among the world's root and tuber crops. It is a starchy corm that people have carried across oceans, renamed in dozens of languages and woven into creation stories. It is also a plant that stings the mouth if it is eaten raw. How did a swamp-loving plant from tropical Asia end up in kitchens from Hawaii to Cyprus to Ghana? Why do Native Hawaiians treat it as something closer to a relative than a vegetable? And what keeps farmers fighting to protect it?

  4122144

• 2. Ancient Footprints

  ›

  At Kilu Cave in the Solomon Islands, traces of taro use date to roughly 28,000 to 20,000 years ago. Archaeologists cannot say whether those plants were wild or tended. That doubt follows the crop everywhere, because taro varies so much in form that wild and cultivated types are hard to tell apart. Other early traces come from the Niah Caves of Borneo, around 10,000 years ago, and from Ille Cave on Palawan, at least 11,000 years old.

  At Kuk Swamp in New Guinea, deposits dated between 8250 BC and 7960 BC show formal agriculture with cultivated plots by about 10,000 years ago. Which plant grew in those plots remains unknown.

  Where taro began is still argued. Scholars have proposed New Guinea, mainland Southeast Asia and northeastern India, and many think it was domesticated independently more than once. Newer studies suggest the wild plant may have a much larger native range than assumed, reaching other parts of Island Southeast Asia. An older view points to the lowland wetlands of Malaysia, where the plant is called talas.

  From about 1300 BC, Austronesian peoples carried taro into the Pacific Islands. There it became a staple for Polynesians, alongside three other plants also called taro: Alocasia macrorrhizos, Amorphophallus paeoniifolius and Cyrtosperma merkusii. Colocasia was the most preferred of the four because it was less likely to carry the irritating raphides found in the others. Pollen and starch residue from Lapita sites fall between 1100 BC and 550 BC. In Micronesia, evidence from the Latte Period, from about 900 to 1521 AD, shows the plant arrived with the settlers. Madagascar received it as early as the 1st century AD.

  The plant also travelled west, to Egypt and the eastern Mediterranean, and from there south and west into East and West Africa. From West Africa it reached the Caribbean and the Americas. The early Romans ate it much as people eat potatoes today and called it colocasia. The Roman cookbook Apicius describes boiling it, serving it with sauces and cooking it with meat or fowl. After the Roman Empire fell, trade with Egypt declined and the vegetable faded from European tables. Spanish and Portuguese sailors later carried it across the Atlantic. In Macaronesia, where it probably arrived after the Portuguese voyages, it is now an important source of carbohydrate.

  3026272824

• 3. What's in a Name

  ›

  In 1769, Captain Cook watched Colocasia plantations in New Zealand, and the English word taro was borrowed from Māori. The same root appears across Polynesia as talo in Samoan and Tongan, and as tao in Marquesan. Linguists trace these forms back to Proto-Polynesian talo, then Proto-Oceanic talos, then Proto-Austronesian *tales. But the sound patterns do not line up neatly. That irregularity suggests the word may have been borrowed from an Austroasiatic language, perhaps in Borneo.

  The scientific name has a different route. The Ancient Greek word kolokasion, meaning lotus root, passed into Latin as colocasia and became the genus name. The species name esculenta is Latin for edible.

  Carl Linnaeus, the 18th-century Swedish biologist, first described two species, Colocasia esculenta and Colocasia antiquorum. Many later botanists decided they were one very variable species. Its correct name is Colocasia esculenta.

  English speakers also know the plant by other names. In Nigeria, Ghana and Anglophone Cameroon it is cocoyam. In Trinidad and Tobago, Jamaica and Saint Lucia it is dasheen. As an ornamental it is called elephant ears, a nickname shared with relatives such as Alocasia, Caladium and Xanthosoma that have large, heart-shaped leaves.

  The word Chinese turns up on separate continents. Malaysians call the plant keladi Cina, literally Chinese yam. In Suriname one form is the Chinese tayer. In Venezuela it is ocumo chino, where chino marks produce considered exotic.

  Name confusion is common. In the Canary Islands ñame means taro, while in other forms of Castilian the same word designates yams.

  5101163

• 4. Leaf, Corm and Sting

  ›

  Needle-shaped raphides made of calcium oxalate fill the cells of raw taro and make it toxic. Cooking removes most of the danger, and so does steeping the corm in cold water overnight. Once prepared, the light purple flesh, coloured by phenolic pigments, tastes sweet and nutty. The starch is easily digestible and its grains are fine and small, so it is often used for baby food.

  In the folklore of the Meitei people of Manipur, an old man and an old woman learn the sting the hard way. Monkeys trick the couple into peeling, boiling and burying their best tubers. At night the monkeys dig up and eat the cooked tubers, then plant inedible wild taro in their place. The plants seem to grow overnight. The couple cook and eat them, and suffer an unbearable tingling in their throats.

  In Vietnam, a variety that grows in shallow water has saponin-like substances that cause a hot, itchy feeling in the mouth and throat. People call it khoai ngứa, literally itchy potato. Northern farmers once cooked its stems and leaves to feed their hogs, since cooking reduced the saponin to a level the animals could eat. That practice is no longer popular.

  Cooked corm supplies 142 calories per 100 grams and is 64 percent water and 35 percent carbohydrate. It gives 25 percent of the daily value of vitamin B6, 20 percent of vitamin E and 21 percent of manganese. Raw leaves are richer still, with vitamin K at 103 percent of the daily value.

  The leaf has a surprise of its own. Researchers found honeycomb-like microstructures on its surface that make it superhydrophobic, with a measured contact angle of around 148 degrees. In Nepal, where almost every part of the plant is eaten, people use large leaves as umbrellas when rain arrives unexpectedly. A Nepali saying draws on the same image: "Our life is as vulnerable as water stuck in the leaf of taro."

  941227546

• 5. Growing and Guarding

  ›

  Taro is one of only a few crops, along with rice and lotus, that thrive under flooding. Paddy cultivation roughly doubles yields, allows out-of-season harvests that can fetch higher prices, and helps control weeds. Polynesian societies built manmade floodplains for the purpose, which they call repo. Dry-land plants mature in six to twelve months, while wetland plants take twelve to fifteen. Farmers harvest when the plant shrinks and the leaves turn yellow. The average yield is around 7 tons per hectare, and the crop does best in deep, moist soil where annual rain exceeds 2,500 millimetres.

  Because taro usually sells for more than other root crops, quality control matters. Markets favour corms of 1-2 kilograms. Buyers expect no bruises, no softness, a round shape and no double-tops, with about 5 centimetres of petiole left attached. The high moisture of the corms invites mold and rot, so they are stored at 10-15 degrees Celsius and 80-90 percent humidity. Corms exported from Fiji to New Zealand travel in wooden boxes in refrigerated containers chilled to around 5 degrees. They stay in good condition for up to six weeks.

  Disease is the larger threat. In the early 1970s, one of the earliest taro breeding programs began in the Solomon Islands to find cultivars resistant to taro leaf blight. In 1993 the blight reached Samoa, and a second program used resistant Asian varieties to restore Samoa's export industry. Fiji stepped into the gap that year and began supplying taro internationally. Almost 80 percent of Fiji's exports come from the island of Taveuni, where the taro beetle Papuana uninodis is absent.

  The genetic picture is uneven. Pacific cultivars give good corms but have a very narrow genetic base. Asian cultivars are more diverse but carry unwanted traits such as suckers and stolons. Experts think there may be 15,000 varieties and hold about 6,000 accessions worldwide. The International Network for Edible Aroids keeps a core collection of 170 cultivars, maintained in vitro at a germplasm centre in Fiji because that is safer and cheaper than field conservation.

  Taro occurs as a diploid with 28 chromosomes and as a triploid with 42. Naturally occurring triploids in India were found to yield significantly better. Breeders have since tried to create triploids artificially by crossing diploids with artificial tetraploids.

  2245212352

• 6. Hawaiian Kalo

  ›

  In the Hawaiian account of ancestry, the first kalo grew from a grave. Papahānaumoku, the earth mother, and Wākea, the sky father, created the islands and a daughter named Hoʻohokukalani. Wākea and his daughter had a child, Hāloanakalaukapalili, meaning Long stalk trembling, but the child was stillborn. After they buried it near their house, a kalo plant rose over the spot. Its slender stems swayed in the wind as if paying homage, and in the center of each leaf water gathered "like a mother's teardrop."

  Their second child, named Hāloa after his older brother, was fed by that kalo, and it became the main food of later generations. The Hawaiian word for family comes from ʻohā, the shoot that grows from the corm. Native Hawaiians say people grow from their family as shoots grow from the plant. This bond is why kalo often appears among sacred offerings.

  The feast known as the lūʻau now takes its newer name from kalo. By ancient custom, fighting is not allowed when a bowl of poi is open. Raising a voice or making rude gestures is also disrespectful, especially in front of an elder.

  Traditional poi starts with steamed corm mashed on a wooden pounding board called papa kui ai. The pounder is a carved pestle, pōhaku kui ai, made from basalt, calcite, coral or wood. The first paste is called pai ai, and water is added while pounding and again before eating. Thicker poi is called one-finger, and thinner poi two-finger or three-finger, after the fingers needed to scoop it up.

  Hawaiians grow kalo in pond fields called loʻi, which need a constant flow of water. About 300 varieties were originally brought to the islands, and roughly 100 remain. Each crop takes seven months, so farmers rotate fields and replant stems.

  Production has fallen sharply. The 1948 high was 14.1 million pounds. The 2003 harvest of 5 million pounds was the lowest since records began in 1946, and 2005 dropped to 4 million, with 97.5 percent going to poi. Urbanization started the decline, followed by the non-native apple snail Pomacea canaliculata and a rot disease caused by a Phytophthora fungus. Pesticides could help, but they are banned in the loʻi because chemicals could wash into streams and the sea.

  In 2006, after activists and farmers objected, the University of Hawaii withdrew its patents on three varieties. It also agreed to stop genetically modifying Hawaii forms of taro. Researchers still experiment with a Chinese form.

  5455565787

• 7. Pacific and Asian Tables

  ›

  In the Cook Islands, taro covers more land than any other crop and anchors both the diet and the export trade. Cooks boil the root, as is standard across Polynesia. They also cook the leaves with coconut milk, onion, and meat or fish. Among the Urapmin people of Papua New Guinea, taro is called ima and sweet potato is called wan. The Urap word for food joins the two names.

  In Samoa, baby leaves and coconut milk are wrapped into parcels called palusami and cooked in an earth oven, the umu. The result is smoky, sweet and creamy. In Tonga, the leaf dish is lū, made on special occasions and especially on Sunday. Cooks fill taro leaves with meat, onions and coconut milk, then wrap the bundle in banana leaf. Lū pulu uses corned beef, lū sipi lamb, lū moa chicken and lū hoosi horse meat.

  On the atolls of Tuvalu, Tokelau and Kiribati, the soil is too infertile for ordinary taro. The traditional staple there is swamp taro, pulaka or babai, which needs three to five years to grow. Because of that wait it is usually reserved for festivities, much like pork.

  In China, taro cake is traditionally eaten at Chinese New Year. Taro paste, a dessert from the Chaoshan region of Guangdong, is the last course at traditional Teochew wedding banquets. McDonald's sells taro-flavored pies in China. In Taiwan, taro was a main staple before the Taiwan Miracle made rice affordable for everyone. It now turns up mostly in desserts, including taro balls and bubble tea.

  In Japan, the related satoimo has been propagated since the late Jōmon period and was a regional staple before rice took over. Cooks usually simmer it in dashi and soy sauce. Koreans call taro toran, meaning earth egg, and stew the corm for the soup toranguk.

  In the Philippines, where the plant is called gabi, the Bicol dish laing cooks taro leaves in coconut milk, sometimes spiced with red hot siling labuyo chilies. Taro also thickens sinigang, the national stew. In Vietnam, chè khoai môn is a sticky rice pudding with taro made for the Tết holiday.

  India holds the widest variety of recipes. In Maharashtra, cooks spread leaves with a gram flour paste, roll them and steam them to make alu chi wadi. In Kerala, steamed corms called chembu kizhangu are eaten with a chutney of green chilies, tamarind and shallots. In Uttarakhand, women worship the saptarshi, the seven sages, on auspicious days and eat only rice with taro leaves. In Bangladesh, kochu is cooked with small prawns or the ilish fish.

  In Nepal, the Tharu people mix roots with dried fish and turmeric and dry them into cakes called sidhara.

  5162646877

• 8. Mediterranean, Africa and Americas

  ›

  On the Greek island of Ikaria, residents credit taro with saving them from famine during World War II. They boil it until tender and serve it as a salad. Cyprus has used the plant since Roman times and has a certified PDO product, kolokasi. Cooks there serve small cormlets called poulles, sauteed, deglazed with dry red wine and coriander seeds, and finished with fresh lemon. Each year the village of Sotira holds a taro festival.

  In Lebanon, kilkass is a popular winter dish. Around Menieh in the north, cooks make bouzmet by drying peeled corms in the sun for a couple of days. They then fry them, add onions, water and chickpeas, and simmer the pot for hours. People treat it as a delicacy that is hard to make. In the Azores, taro is called inhame, and cooks fry the steamed corm and sprinkle it with sugar, cinnamon and nutmeg. In Egypt, where the name is qolqas, the corms grow larger than those in North American supermarkets.

  In Ghana, cocoyam stands in for plantain when making fufu while plantains are out of season. The leaves, called kontomire, go into palaver sauce and egusi stew. In South Africa the plant is amadumbe in Zulu. In Kenya, Uganda and Tanzania, people usually boil it and eat it with tea.

  Across the Atlantic, William Bartram saw residents of the South Carolina Sea Islands eating roasted roots in 1791. They called the plant tanya. In the 1920s the Secretary of the Florida Department of Agriculture promoted dasheen for growing in muck fields. At Fellsmere, Florida, farmers used it in place of potatoes and dried it into a flour said to make excellent pancakes when mixed with wheat flour.

  In Haiti, grated corm is deep-fried into acra, a popular street fritter. In Trinidad and Tobago, dasheen leaves go into callaloo with okra, coconut milk and herbs. Indo-Trinidadians fry the leaves in split pea batter to make saheena. In Suriname, Maroon communities in the interior favor one cultivar because high water levels do not harm it. In Brazil, inhame and cará are both common names, and Brazilians generally think of carás as potato-shaped and inhames as more oblong.

  Not every place welcomes the plant. In Western Australia, the Northern Territory, Queensland and New South Wales, the common variety is an invasive weed. In the southeastern United States, populations grow near drain ditches and bayous in Houston, Texas.

  7913848538