1. Family: Araceae Juss.
    1. Genus: Alocasia (Schott) G.Don
      1. Alocasia macrorrhizos (L.) G.Don

        Elephant ear taro is a giant plant with distinctive leaves and is valued as an ornamental. The swollen underground stems are used for food and animal fodder, and the roots and leaves are used medicinally in some countries. For example, in Hawaii, it has been used to treat digestive complaints, as a topical dressing for burns, and as a love charm. In the Philippines, the leaf stalks have been used to relieve toothache and on Java the roots and leaves have been used to relieve pain and redness. The rhizomes contain an anti-fungal protein called alocasin.

    [KSP]

    Kew Species Profiles

    General Description
    Elephant ear taro is a massive aroid with a spectacular cluster of upwardly pointing, arrow-shaped leaf blades which can reach one metre in length.

    Elephant ear taro is a giant plant with distinctive leaves and is valued as an ornamental. The swollen underground stems are used for food and animal fodder, and the roots and leaves are used medicinally in some countries. For example, in Hawaii, it has been used to treat digestive complaints, as a topical dressing for burns, and as a love charm. In the Philippines, the leaf stalks have been used to relieve toothache and on Java the roots and leaves have been used to relieve pain and redness. The rhizomes contain an anti-fungal protein called alocasin.

    Species Profile

    Geography and distribution

    Alocasia macrorrhizos is found throughout IndoMalesia and Oceania. It is not clear where, if anywhere, this species occurs truly wild. It has evidently been distributed widely in tropical Asia in prehistoric times as a subsistence crop and is now pantropical by introduction as an ornamental.

    Description

    Elephant ear taro is a massive aroid with a spectacular cluster of upwardly pointing, arrow-shaped leaf blades which can reach one metre in length. The flowering parts are often inconspicuous, and are partly concealed by the floral bract. This bends back and then falls off at maturity though, to reveal a spike of red berries, each of which contains several pale brown seeds.

    Elephant ear taro is a massive herb, forming a thick erect trunk in large plants and reaching four metres in height. The leaves are held erect, with petioles (leaf stalks) up to 130 cm long. The leaves are stout, with sheathing in the lower part. The leaf blades are arrow-shaped, bluntly triangular in general outline with somewhat rounded basal lobes. There are about nine main veins, diverging at an angle of about 60 degrees.

    The inflorescences (flower stalks) occur in pairs amongst the leaf bases, preceded by a cataphyll (scale leaf). The spathe (floral bract) is about 13 to 35 cm long, constricted about 1/6 of the way from the base, with the lower part folded into a green tube. The limb is oblong, pale yellow, cowl-like when in flower, then bending back and deciduous. The spadix (flower spike) is slightly shorter than the spathe. The lowermost 1 to 2 cm of the spadix is female and covered with about 30 pistils (female parts). Each pistil consists of a pale green ovary with a yellow 3 to 5 -lobed stigma sitting directly on it. Above the female flowers there is a zone with about four whorls of white sterile organs corresponding in position to the spathe constriction. The next floral zone is male, covered with tightly packed white rhomboid to hexagonal male flowers. At the tip of the spadix is a yellowish appendix, which is at least half the spadix length and covered with tiny irregular furrows.

    The fruit is a few-seeded red berry, which when ripe is exposed by the recurving segments of the lower spathe tube, which detaches on maturity. Each berry has several pale brown seeds about 4 mm in diameter.

    Uses

    The rhizomes (swollen underground stems) of Alocasia macrorrhizos are traditionally eaten as a starchy food throughout IndoMalesia and Oceania. It is thought to have once been a major staple food in Micronesia that became extinct there prior to the introduction of related taro species (for example Colocasia esculenta). The rhizomes are used for animal feed and famine food for people. They require prolonged preparation and boiling or roasting to rid them of stinging calcium oxalate crystals.

    Today, Alocasia macrorrhizos is a popular ornamental plant grown for its large foliage and striking aroid inflorescences. It has also shown promise in sewerage treatment, as it grows rapidly in wetland conditions and has a propensity to accumulate metal contaminants such as zinc.

    Ecology
    Tropical humid forest. Commonly found growing around human settlements.
    Conservation
    Not of conservation concern.
    Hazards

    The rhizomes (swollen underground stems) contain stinging calcium oxalate crystals.

    [KSP]
    Use
    Food, medicine, ornamental.

    Images

    Distribution

    Found In:

    Bismarck Archipelago, Borneo, Maluku, New Guinea, Philippines, Queensland, Solomon Is.

    Introduced Into:

    Andaman Is., Assam, Bangladesh, Brazil Northeast, Cambodia, Caroline Is., Chagos Archipelago, China South-Central, China Southeast, Cook Is., Costa Rica, Cuba, Dominican Republic, East Himalaya, Fiji, Gilbert Is., Guinea, Gulf of Guinea Is., Hainan, Haiti, Hawaii, Honduras, India, Jamaica, Jawa, Laccadive Is., Laos, Leeward Is., Lesser Sunda Is., Malaya, Maldives, Marianas, Marshall Is., New Caledonia, Nicaragua, Niue, Paraguay, Portugal, Puerto Rico, Samoa, Seychelles, Society Is., Sri Lanka, St.Helena, Sudan, Sulawesi, Sumatera, Taiwan, Thailand, Tibet, Tokelau-Manihiki, Tonga, Trinidad-Tobago, Vanuatu, Venezuela, Venezuelan Antilles, Vietnam, Windward Is.

    Common Names

    English
    Elephant ear taro

    Alocasia macrorrhizos (L.) G.Don appears in other Kew resources:

    Date Identified Reference Herbarium Specimen Type Status
    Oct 1, 1998 Bull, W. [s.n.], Rio de Janeiro K001067608 Unknown type material
    Oct 1, 1998 Bull, W. [s.n.], Rio de Janeiro K001067609 Unknown type material
    Oct 1, 1998 Bull, W. [s.n.], Rio de Janeiro K001067610 Unknown type material
    Oct 1, 1998 Bull, W. [s.n.], Rio de Janeiro K001067611 Unknown type material
    Oct 1, 1998 Bull, W. [s.n.], Rio de Janeiro K001067612 Unknown type material
    Oct 1, 1998 Bull, W. [s.n.], Rio de Janeiro K001067613 Unknown type material
    Oct 1, 1998 Bull, W.? [s.n.] K000291562 Unknown type material
    Oct 1, 1998 Bull, W.? [s.n.] K000291563 Unknown type material
    Harley, W.J. [2135], Liberia 25022.000
    25830.000
    Forman, L.L. [44], Indonesia 18969.000

    First published in Hort. Brit., ed. 3: 631 (1839)

    Accepted in:

    • [3] Darbyshire, I., Kordofani, M., Farag, I., Candiga, R. & Pickering, H. (eds.) (2015) The Plants of Sudan and South Sudan . Kew publishing, Royal Botanic Gardens, Kew.
    • [7] (2012) Flora of Thailand 11(2): 101-325. The Forest Herbarium, National Park, Wildlife and Plant Conservation Department, Bangkok.
    • [10] Lambdon, P. (2012) Flowering plants & ferns of St Helena . Pisces publications for St Helena nature conservation group.
    • [12] Mansor, M., Boyce, P.C., Othman, A.S. & Sulaiman, B. (2012) The Araceae of peninsular Malaysia . Penerbit Universiti Sains Malaysia.
    • [14] (2011) Acta Phytotaxonomica et Geobotanica 61: 40-50
    • [15] (2011) Bothalia 41: 41-82
    • [16] (2010) Flora of China 23: 1-515. Missouri Botanical Garden Press, St. Louis.
    • [17] (2009) Pleione 3: 190-200
    • [18] (2009) Scripta Botanica Belgica 41: 1-517
    • [20] (2008) Thai Forest Bulletin (Botany) 36: 1-17
    • [21] Hokche, O., Berry, P.E. & Huber, O. (eds.) (2008) Nuevo Catálogo de la Flora Vascular de Venezuela . Fundación Instituto Botánico de Venezuela.
    • [23] Nelson Sutherland, C.H. (2008) Catálogo de las plantes vasculares de Honduras. Espermatofitas . SERNA/Guaymuras, Tegucigalpa, Honduras.
    • [24] (2006) Rojasiana 7(2): 51-62
    • [25] (2005) Contributions from the United States National Herbarium 52: 1-415
    • [26] (2005) Harvard Papers in Botany 10: 95-116
    • [29] (2003) Manual de Plantas de Costa Rica 2: 1-694. Missouri Botanical Garden Press, St. Louis.
    • [30] Albano, P.-O. (2003) La Conaissance des Plantes Exotiques . Édisud, Aix-en-Provence.
    • [31] Govaerts, R. & Frodin, D.G. (2002) World Checklist and Bibliography of Araceae (and Acoraceae) . The Board of Trustees of the Royal Botanic Gardens, Kew.
    • [32] (2001) Bangladesh Journal of Plant Taxonomy 8(2): 19-34
    • [33] (2001) Monographs in Systematic Botany from the Missouri Botanical Garden 85: i-xlii, 1-2666
    • [38] Welsh, S.L. (1998) Flora Societensis . E.P.S. Inc. Utah.
    • [40] Govaerts, R. (1995) World Checklist of Seed Plants 1(1, 2): 1-483, 1-529. MIM, Deurne.
    • [41] MacKee, H.S. (1994) Catalogue des plantes introduites et cultivées en Nouvelle-Calédonie , ed. 2: 1-164. Museum national d'histoire naturelle, Paris.
    • [42] (1991) Palmarum Hortus Francofurtensis 3: 1-108
    • [44] (1987) Atoll Research Bulletin 295: 1-33
    • [46] (1971) New Zealand Journal of Botany 9: 576-609
    • [47] (1970) Bulletin, New Zealand Department of Scientific and Industrial Research 200: 1-321

    Literature

    • [1] (2016) Phytotaxa 250: 1-431
    • [2] Sykes, W.R. (2016) Flora of the Cook Islands . National Tropical Botanical Garden, Hawaii.
    • [4] Darbyshire, I., Kordofani, M., Farag, I., Candiga, R. & Pickering, H. (eds.) (2015) The Plants of Sudan and South Sudan . Kew publishing, Royal Botanic Gardens, Kew.
    • [5] (2013) Rodriguésia; Revista do Instituto de Biologia Vegetal, Jardim Botânico e Estaçao Biologica do Itatiaya 64: 445-477
    • [6] Leti, M., Hul, S., Fouché, J.-G., Cheng, S.K. & David, B. (2013) Flore photographique du Cambodge . Éditions Privat, Toulouse.
    • [8] (2012) Korean Journal of Plant Taxonomy 42: 222-246
    • [9] (2012) Smithsonian Contributions to Botany 98: 1-1192
    • [11] Lambdon, P. (2012) Flowering plants & ferns of St Helena . Pisces publications for St Helena nature conservation group.
    • [13] Mansor, M., Boyce, P.C., Othman, A.S. & Sulaiman, B. (2012) The Araceae of peninsular Malaysia . Penerbit Universiti Sains Malaysia.
    • [19] (2008) Journal of Economic and Taxonomic Botany 32: 403-500
    • [22] Hokche, O., Berry, P.E. & Huber, O. (eds.) (2008) Nuevo Catálogo de la Flora Vascular de Venezuela . Fundación Instituto Botánico de Venezuela.
    • [27] Ivancic, A., Roupsard, O., Garcia, J.Q., Lebot, V., Pochyla, V. & Okpul, T. (2005). Thermogenic flowering of the giant taro (Alocasia macrorrhizos, Araceae). Canadian Journal of Botany 83: 647 – 655 [for flowering behaviour]
    • [28] Samake, M., Wu, Q.-T., Mo, C.-H-. & Morel, J.-L. (2004). Plants grown on sewage sludge in South China and its relevance to sludge stabilization and metal removal. Journal of Environmental Sciences 15: 622-627.

    • [34] Lee, R.A., Balick, M.J., Ling, D.L., Sohl, F., Brosi, B.J. & Raynor, W., (2001). Cultural dynamism and change: an example from the Federated States of Micronesia. Economic Botany 55: 9-13.
    • [35] Hay, A. (1999). The genus Alocasia (Araceae-Colocasieae) in the Philippines. Gardens Bull. Singapore. 51: 1 - 41.
    • [36] Sheppard, C.R.C. & Seaward, M.R.D. (eds.) (1999) Ecology of the Chagos archipelago . Westbury Academic & Scientific Publishing, Otley.
    • [37] Hay, A. (1998). The genus Alocasia (Araceae-Colocasieae) in West Malesia and Sulawesi. Gardens Bull. Singapore. 50: 221-334. [for descriptive and geographical information]
    • [39] (1995) Journal of Economic and Taxonomic Botany 19: 235-250
    • [43] Hay, A. & Wise, R. (1991). The genus Alocasia (Araceae) in Australasia. Blumea. 35: 499-545 [for descriptive and geographical information]
    • [45] Quisumbing, E. (1978). Medicinal Plants of the Philippines. Katha, Quezon City.
    • [48] (1957) Atoll Research Bulletin 58: 1-37
    • [49] Akana, A. (1922). Hawaiian Herbs of Medicinal Value. Pacific Book House, Honolulu.

    Sources

    International Plant Names Index
    The International Plant Names Index (2016). Published on the Internet http://www.ipni.org
    [A] © Copyright 2016 International Plant Names Index. https://creativecommons.org/licenses/by/3.0

    Kew Species Profiles
    Kew Species Profiles
    [B] http://creativecommons.org/licenses/by-nc-sa/3.0
    [C]

    World Checklist of Selected Plant Families
    World Checklist of Selected Plant Families(2016). Published on the Internet http://apps.kew.org/wcsp/
    [D] See http://kew.org/about-kew/website-information/legal-notices/index.htm You may use data on these Terms and Conditions and on further condition that: The data is not used for commercial purposes; You may copy and retain data solely for scholarly, educational or research purposes; You may not publish our data, except for small extracts provided for illustrative purposes and duly acknowledged; You acknowledge the source of the data by the words "With the permission of the Trustees of the Royal Botanic Gardens, Kew" in a position which is reasonably prominent in view of your use of the data; Any other use of data or any other content from this website may only be made with our prior written agreement. http://creativecommons.org/licenses/by-nc-sa/3.0
    [E] © Copyright 2016 International Plant Names Index and World Checkist of Selected Plant Families. https://creativecommons.org/licenses/by/3.0