Taro: Origins and Development

  • Peter J. MatthewsEmail author
  • Dzu V. Nguyen
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-51726-1_2190-2

Basic Species Information

Taro (less commonly: cocoyam, dasheen, eddoe) (English), kolokasi (Greek), qolqas (Arabic), kachu (Bengalese), arvi (Hindi), pein-u (Burmese), yu (Chinese), satoimo (Japanese), khoai nuoc (Vietnamese), gabi (Tagalog), kaladi (Malay), talas (Palawan, Bahasa), taro (Maori, Samoan), ma (Papua New Guinea), gwaza (Hausa), iso koko (Yoruba), ede epi (Igbo), and mayugwa (Zanzibar). The genus Colocasia (L.) contains at least nine and perhaps many more distinct species, all of which are found in humid to semiaquatic habitats in Southeast Asia to Southern China. They are soft acrid herbs, often 0.5–2 m tall, leaves large, heart-shaped, with blades supported on long centrally inserted petioles (hence peltate) above an erect or underground corm. Male and female flowers appear on the same inflorescence (spadix with spathe, raised on a peduncle). After pollination by insects, numerous berries with many small seeds are produced. Some species, including taro (C. esculenta, Figs. 1 and 2), display waxy, non-shining leaves that repel water (wax is on micro-hairs that reduce reflection), while others display non-waxy, shiny, wettable leaves (e.g., C. lihengiae, Fig. 3). On taro, two to several fruiting heads may appear in sequence in one season from a single axil. Vegetative propagation of taro is by side-corms with many buds (many or most cultivars) or by long stolons with many nodes (some cultivars and most wild forms).
Fig. 1

Wild taro (C. esculenta) in swamp with Pandanus in lowland rainforest, Daintree National Park, Australia. (Photo: Matthews 2008)

Fig. 2

Removing acrid skin from the starchy corm of cultivated taro, Kokoda Valley, Papua New Guinea. (Photo: Matthews 2008). Starchy residues like those attached to the knife here have been reported archaeologically on stone tools

Fig. 3

Colocasia lihengiae Long and Liu, wild in Ba Vi National Park, Vietnam. (Nguyen 2005; Photo: Matthews and Nguyen 2011)

Taxonomy and Geographical Distribution

Taro was first described by Linnaeus in 1753 based on material derived from the Mediterranean region, where it has been cultivated since antiquity. He put the species in genus Arum under the name Arum esculentum L. In 1832, Schott transferred taro from Arum to a new genus, Colocasia Schott, based on the type species Colocasia antiquorum Schott, a name later understood as a synonym for C. esculenta (L.) Schott. Many different names have existed for the same plant, including Caladium esculentum (L.) Vent. 1801, Colocasia esculenta var. aquatilis Hassk. 1840, C. antiquorum var. aquatilis (Hassk.) Krause 1920, and C. esculenta var. antiquorum (Schott) Hubb. and Rehder 1932. Early taxonomists erected many species of Colocasia based on collections of wild plants and diverse cultivated forms of what is now called taro (C. esculenta). Recent work in mountainous regions of Southeast Asia has led to the discovery and description of further wild species. Consensus is lacking on the full number of distinct species; nine are noted here and more certainly exist:
  1. 1.

    Colocasia esculenta (L.) Schott 1832, highly polymorphic (Plucknett 1983) with diverse wild-type and domesticated forms; cultivated in most tropical to warm-temperate regions of the world; possibly evolved in low mountains of Southeast Asia (vicinity of other wild species in mountains), now distributed in natural and disturbed habitats in subtropical to tropical regions from India to China, Australia, and Melanesia (the likely natural range, Matthews et al. 2017) and notably absent from Taiwan as a wild plant

     
  2. 2.

    C. formosana Hayata 1919, abundant and widespread in Taiwan; also present in Luzon; forms a morphologically homogeneous wild population and is not known in domesticated form; morphologically distinct, but minimally so, from wild C. esculenta (Matthews et al. 2015).

     
  3. 3.

    C. fallax, Schott 1859, wild in Himalaya

     
  4. 4.

    C. affinis Schott 1859, wild in mainland Southeast Asia, lower altitudes

     
  5. 5.

    C. lihengiae Long and Liu 2001 wild in mountains, northern Vietnam to Yunnan, China, and Northeast India

     
  6. 6.

    C. menglaensis Yin, Li, and Xu 2004, wild in mountains, northern Vietnam to Yunnan, China

     
  7. 7.

    C. yunnanensis Long and Cai 2006, wild in mountains, northern Vietnam to Yunnan, China

     
  8. 8.

    C. oresbia Hay 1996, wild on Mt. Kinabalu, Borneo.

     
  9. 9.

    C. gigantea (Blume) J. D. Hook. 1893, a leaf vegetable (petiole only) in Southeast to East Asia and especially popular in Vietnam; wild in karst landscapes of mainland Southeast Asia; a taxonomic and genetic outlier, distant from other Colocasia species

     

Major Domestication Traits

Rumphius (seventeenth century) may have been the first author to describe with words and illustration a natural wild form of taro (Caladium aquatile; syn. C. esculenta var. aquatilis; cf. Matthews 1991) in Ambon, eastern Indonesia; he saw wild taro growing along rivers, and it was used as fodder for pigs, a usage that is widespread today in Southeast Asia. Wild taro is very acrid, like most Araceae, and is widely known as a famine food that requires special care in the selection and preparation of parts eaten (corms, leaves, stolons). Major domestication traits are:
  1. 1.

    Reduction in acridity of raw tissue or an increase in the susceptibility of the acrid factor (an enzyme) to heat (cooking) or both.

     
  2. 2.

    Increase in the bulk of the starchy corms, with diverse associated changes in flavor and texture.

     
  3. 3.

    Distinctive green-white, purple-red, and yellow-orange colors in leaves, stolons, corms, and inflorescences; color variation aids cultivar identification and has aesthetic appeal in gardens and on plate.

     
  4. 4.

    Cold adaptation (many small side-corms) and day-length sensitivity in northern temperate cultivars.

     

Acridity helps protect against herbivores, reducing costs for cultivation and storage but increasing costs for processing and consumption. In some cultivars the reduction favors consumption of starchy corms and green vegetable parts (leaves, stolons); in others it may favor corms or green parts but not both. According to cultivar, the corms, side-corms, or leaves (blade or petiole) are main parts eaten; the stolons and spathes of some cultivars are also eaten. Throughout Southeast Asia, commensal wild taro populations with relatively low acridity are harvested as a green vegetable food and as a fodder for pig, making taro perhaps the most abundant green vegetable in the region.

Timing and Tracking Domestication

Cultivars in Eurasia are very ancient since taro is mentioned in ancient texts that date back to around 2000 years ago in both China and the eastern Mediterranean (Matthews 2006). Northern, temperate-adapted cultivars of taro may have originated in the northern margins of the natural range, in eastern Himalaya, where taro could breed, where triploids often appeared, and where farmers could select traits favorable to winter storage, spring propagation, and summer cultivation. The earliest association of taro with human settlement, from 10,000 years ago, has been found at Kuk Swamp in Papua New Guinea (Golson et al. 2017). In Papua New Guinea, taro used at early dates could have been a natural wild form or could have been undergoing domestication in response to changes in landscape management, cultivation methods, cooking methods, and food preferences.

Genetic studies have shown that taro cultivars are very diverse and form a number of distinct gene pools; the great diversity within diploid and triploid cultivars (2n = 28, 2n = 42) indicates domestication many times. Wild populations have not been studied in enough detail, or in enough places, to identify source regions and routes of movement. Since cultivars are carefully maintained as clones, some may be hundreds if not thousands of years old. Clones identified by the analysis of multi-locus genotypes have spread in many different directions, over vast distances, with trade and human migration (Chair et al. 2016). The antiquity of taro in Africa is much debated. Wild populations are not known there, and the crop was possibly introduced from multiple directions at different times: overland from West Asia, via the Indian Ocean from Southeast Asia, and via the Mediterranean Sea to North Africa and the Iberian Peninsula. Taro first reached the Caribbean and Central America as a food of slaves carried from West Africa.

Cross-References

References

  1. Chaïr, H., R.E. Traore, M.F. Duval, R. Rivallan, A. Mukherjee, and L.M. Aboagye. 2016. Genetic diversification and dispersal of taro (Colocasia esculenta (L.) Schott). PLoS One 11 (6): e0157712.  https://doi.org/10.1371/journal.pone.0157712.CrossRefGoogle Scholar
  2. Golson, J., T. Denham, P. Hughes, J.D. Muke, and P. Swadling. 2017. Ten thousand years of cultivation at Kuk Swamp in the highlands of Papua New Guinea, Terra Australis 46. Acton: A.C.T. ANU Press.CrossRefGoogle Scholar
  3. Matthews, P.J. 1991. A possible tropical wildtype taro: Colocasia esculenta var. aquatilis. Bulletin of the Indo-Pacific Prehistory Association 11: 69–81.CrossRefGoogle Scholar
  4. Matthews, P.J. 2006. Written records of taro in the eastern Mediterranean. In Proceedings of the fourth international congress of ethnobotany (ICEB 2005), ed. Z.F. Ertug, 419–426. Istanbul: Yayinlari.Google Scholar
  5. Matthews, P.J., V.D. Nguyen, D. Tandang, E.M. Agoo, and D.A. Madulid. 2015. Taxonomy and ethnobotany of Colocasia esculenta and C. formosana (Araceae): Implications for the evolution, natural range, and domestication of taro. Aroideana 38E: 153–176.Google Scholar
  6. Matthews, P.J., P.J. Lockhart, and I. Ahmed. 2017. Phylogeography, ethnobotany and linguistics: Issues arising from research on the natural and cultural history of taro, Colocasia esculenta (L.) Schott. Man in India 97: 353–380.Google Scholar
  7. Nguyen, V.D. 2005. New species of genus Colocasia (Araceae) for flora of Vietnam. VNU Journal of Science 11 (3): 54–56.Google Scholar
  8. Plucknett, D.L. 1983. Taxonomy of the genus Colocasia. In Taro: A review of Colocasia esculenta and its potentials, ed. J.-K. Wang, 14–19. Honolulu: University of Hawaii Press.Google Scholar

Further Reading

  1. Grimaldi, I.M. Taro across the oceans: Journeys of one of our oldest crops. In News from the past: Progress in African archaeobotany, Advances in archaeobotany, ed. U. Thanheiser, vol. 3, 67–82. Eelde: Barkhuis.Google Scholar
  2. Rao, V.R., P.J. Matthews, P.B. Eyzaguirre, and D. Hunter, eds. 2010. The global diversity of taro: Ethnobotany and conservation. Rome: Bioversity International.Google Scholar
  3. Rumphius, G. E. 2011. (17th C) The Ambonese herbal. Translated, annotated and introduced by E. M. Beekman. New Haven: Yale University Press.Google Scholar
  4. Spriggs, M., D.A. Addison, and P.J. Matthews, eds. 2012. Irrigated taro (Colocasia esculenta) in the Indo-Pacific: Biological, social and historical perspectives, 307–340. Osaka: National Museum of Ethnology.Google Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.National Museum of EthnologyOsakaJapan
  2. 2.Institute of Ecology and Biological Resources and Graduate University of Science and Technology (Vietnam Academy of Science and Technology)HanoiVietnam

Section editors and affiliations

  • Dorian Q. Fuller
    • 1
  1. 1.Institute of ArchaeologyUniversity College LondonLondonUK