1. Family: Araceae Juss.
    1. Genus: Amorphophallus Blume ex Decne.
      1. Amorphophallus paeoniifolius (Dennst.) Nicolson

        Elephant yam is a striking aroid with a flower spike crowned with a bulbous maroon knob and encircled by a fleshy maroon and green-blotched bract. The solitary leaf, which emerges after the flowering parts, resembles a small tree.

    [CATE]

    CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

    Phenology
    Fl. Apr–May, fr. Oct–Nov. The leaf is present from September to April.
    General Description
    Tuber dark brown, depressed globose, ca. 20cm high, to ca. 30cm in diam., weighing up to ca. 15kg; root scars prominent, annulate; offsets produced every season, thick and rhizomatous, to ca. 10 × 4cm. Leaves 1 or 2; petiole background pale to dark green or blackish green, usually with large and small pale blotches and numerous tiny dark dots, large blotches often confluent, especially near base, petiole to ca. 2 m × 20cm, shallowly corrugate to strongly echinate-verrucate; leaf blade highly dissected, to ca. 3m in diam.; rachises narrowly or broadly winged almost to base; leaflets abaxially mid-green or pale green, adaxially mid-green, orbicular, oval, ovate, obovate, elliptic, elliptic-oblong, elliptic-lanceolate, or lanceolate, 3–35 × 2–12cm, apex acuminate. Inflorescence shortly pedunculate; peduncle 3–20 × 1–8cm, usually paler and more glabrous than petioles. Spathe campanulate, broader than long, 10–45 × 15–60cm, base and limb often separated by a shallow constriction; limb spreading, background ranging from pale green to dark brown, usually with both large and small, orbicular paler spots, base inside proximal part deep maroon, distal part dirty whitish or very pale pinkish, limb outside as base but with more prominent maroon flushes, especially near margin, limb inside usually glossy dark maroon, strongly undulate, base outside very variable, base within densely verrucate, verrucae variable, mostly conic, fleshy. Spadix giving off a stench of rotting meat, sessile, shorter or longer than spathe, 7–70cm; female zone cylindric, 3–25 × 1–12cm, flowers congested or slightly distant; ovary entirely pale green or largely maroon with a whitish base, depressed, orbicular in cross section, 1.5–2.5mm high, 3–5mm in diam., 2- or 3-loculed; style maroon, 3–15mm, slender, 1–1.5mm in diam.; stigma pale or deep yellow, oval or triangular in cross section, large, 3–5mm high, 4–7mm in diam., often strongly laterally compressed, then cordate in longitudinal section, verruculose, shallowly or deeply 2- or 3-lobed, lobes rounded or conic, sometimes with a strong groove on outward side; male zone cylindric or strongly obconic, 2.5–15cm, 1–10cm in diam. at base, 1–20cm in diam. at apex, flowers congested; male flowers consisting of 4–6 stamens; stamens 4–6mm; filaments ca. 0.5 mm, connate; anthers off-white, cylindric, 3.5–5.5 × ca. 1.5mm, subtruncate; pollen psilate; appendix very variable, glossy dark maroon, rarely pinkish or yellow, inflated, globose, depressed globose, ovoid, or triangular-conic (pyramidal), 1.5–30cm, 1.2–30cm in diam. (slightly above base), minutely granulate, glabrous or with various folds and/or irregular shallow depressions, base often with flattened, staminodal structures, apex obtuse or ± acute. Infructescence long pedunculate; peduncle stretching strongly after fertilization, 20–100cm, becoming uniformly tan, with very numerous narrow, transverse cracks; fruiting zone cylindric, 10–50 × 3–8cm. Berries closely set or slightly distant, ripening from green through yellow to bright red, elongate, 1.5–2 cm × 8–10mm. Tuber flattened globose, 10-40 cm in diameter, brown. LEAF solitary, more rarely 2; 2-3 membranous cataphylls, of different lengths, accompanying the leafs or the inflorescence; petiole 50-150 x 2-4 cm in diameter, scabrid to slightly verruculose, pale green to greenish, with paler mottlings. Leaf blade 50-150 cm diameter, pale green, divided into three main parts, the segments divided, bifurcate and pinnatisect, incisions up to the primary vein; lobes oblong elliptic, cuspidate to acuminate, 5-15 cm long, oblique and decurrent on one side. INFLORESCENCE: Peduncle short, 5-20 cm long, ca. 3 cm wide, mottled reaching 120 cm in fruit. Spathe campanulate to subcampanulate, coriaceous to fleshy, 20-30 x 25-35 cm, margin ± curved and pleated, the external surface greenish to reddish and mottled whitish, the internal surface purple and verruculose at the base, yellow in the central zone, the edges purple on the upper part. Spadix 25-30 cm long; female zone cylindric, 5-12 cm; male zone obconic, 4-6 x 2-4 (at the base), 4-6 (towards the top) cm; Appendix globose to subglobose, or globose-conoid 7-15 x 10-15 cm (at the base), purple, ± reddish. Male flowers 4-5 mm tall; anthers subsessile, oblong. Female flowers 10-17 mm long; ovary 2-3 mm tall, purple, usually 2-locular (rarely 3); Style purple, 8-14 mm long, cylindric; stigma yellowish with 2-3 lobes ca. 1.5 mm diameter. INFRUCTESCENCE: Berries ovoid to oblong, red, 10-13mm long; 2 seeds (rarely 3). Chromosome number 2n=28.
    Habitat
    Secondary conditions, secondary forests or highly disturbed areas, in dappled shade or fully exposed. Terrestrial or on humus accumulated on rocks; shady places.
    Vernacular
    you bing mo yu
    [FTEA]

    Araceae, S.J. Mayo. Flora of Tropical East Africa. 1985

    Diagnostic
    It is quite distinct from the native East African species in the subglobose to broadly conic, coarsely furrowed and crumpled spadix appendix, surrounded by a campaniform purple spathe.
    [KSP]

    Kew Species Profiles

    General Description

    Elephant yam is a striking aroid with a flower spike crowned with a bulbous maroon knob and encircled by a fleshy maroon and green-blotched bract. The solitary leaf, which emerges after the flowering parts, resembles a small tree.

    Amorphophallus paeoniifolius has been in cultivation throughout tropical Asia for centuries. The tubers are the third most important carbohydrate source after rice and maize in Indonesia. They are also consumed widely in India and Sri Lanka, although elsewhere they are seen as a famine crop, to be used when more popular staples, such as rice, are in short supply.

    Elephant yam belongs to the same genus as the crowd-pulling titan arum (Amorphophallus titanum). It should not be confused with Dioscorea species, which are also known by the common name yam, but belong to a different plant family (Dioscoreaceae). In particular it should not be confused with elephant's foot yam (Dioscorea elephantipes) from South Africa.

    Elephant yam has medicinal properties and is used in many Ayurvedic (traditional Hindu) preparations. The tubers are considered to have pain-killing, anti-inflammatory, anti-flatulence, digestive, aphrodisiac, rejuvenating and tonic properties. They are traditionally used in the treatment of a wide range of conditions including parasitic worms, inflammation, coughs, flatulence, constipation, anaemia, haemorrhoids and fatigue.

    Further research is needed to determine the pharmacological properties of elephant yam.

    Species Profile
    Geography and distribution

    Amorphophallus paeoniifolius is considered to be native to southern China (including Taiwan), Bangladesh, India, Sri Lanka, Laos, Burma, Thailand, Vietnam, Borneo, Java, Peninsular Malaysia, Philippines, Sulawesi, Sumatra, New Guinea, northern Australia, Fiji and Samoa.

    It is found in secondary forest or highly disturbed areas, up to 800 m above sea level.

    It is considered naturalised in Madagascar and the Seychelles.

    Elephant yam has been in cultivation throughout tropical Asia for centuries. It has been widely transported by humans and easily escapes from cultivation to become naturalised, so that its natural distribution is not clear.

    Description

    Overview: Perennial herb. A single inflorescence (flowering structure) is produced, followed by a solitary leaf. After the growing season, this dies back to an underground storage organ (tuber).

    Tuber (thickened part of underground stem): Dark brown, flattened-globe-shaped, up to 50 × 30 cm with prominent root scars. Weighing up to about 15 kg.

    Leaves: Usually one (sometimes two) per tuber. Petiole (leaf stalk) up to 2 m tall and 20 cm in diameter with rough, warty surface. Background colour pale to dark green or blackish-green with pale blotches and numerous tiny dark dots. Leaf blade up to 3 m in diameter and deeply divided into segments. Leaflets up to 35 × 12 cm.

    Spadix (flower spike): Up to 70 cm long. The lowermost portion of the spadix is female and is covered with pistils (female parts). Each pistil consists of a pale green or maroon ovary with a maroon stalk (style) and two- or three-lobed yellow head (stigma). The next floral zone is male and contains tightly-packed yellowish stamens. At the tip of the spadix is a bulbous, dark maroon, rounded to deeply wrinkled appendix.

    Spathe (bract surrounding spadix): Bell-shaped, broader than long, up to 45 × 60 cm, pale green to dark brown with paler blotches on exterior. Opening outwards to form a frilled, glossy maroon, collar-like structure around the spadix. Basal portion of interior pale green-yellow.

    Fruits: About 2 × 1 cm, bright red when ripe. Borne on a spike up to 50 cm long and 8 cm in diameter, the fruiting part held aloft on a peduncle (stalk) 20-100 cm long.

    The flower spike (spadix) emits an odour reminiscent of rotting flesh, which attracts pollinators such as carrion flies and beetles.

    Uses

    Elephant yam is widely cultivated for its edible tubers, which are an important source of carbohydrate in India and Indonesia and a valued secondary crop throughout tropical Asia. It can be found on sale further afield (including Hounslow, not far from Kew in the UK) in international food markets.

    It is also widely used as fodder.

    Elephant yam is cultivated as an ornamental for its striking compound foliage and unusual and dramatic flowering and fruiting structures.

    This species at Kew

    Elephant yam can be seen growing in the Tropical Carnivorous Zone (Zone 8) of the Princess of Wales Conservatory at Kew.

    This newly redeveloped zone is home to many other species including Nepenthes truncata , N. rafflesiana , N. veitchii , N. bicalcarata and the recently described N. robcantleyi . The zone also features voodoo lily ( Amorphophallus variabilis ) and a new hybrid at Kew A. decus-silvae × gigas , plus a range of epiphytic ferns and orchids including Bulbophyllum species.

    Dried and alcohol-preserved specimens of Amorphophallus paeoniifolius are held in Kew's Herbarium. The details, including images, of some of these can be seen online in Kew's Herbarium Catalogue.

    Distribution
    Australia, China, India, Laos, Philippines, Taiwan, Thailand, Vietnam
    Ecology
    Secondary forest or highly disturbed areas.
    Conservation
    Not considered to be threatened.
    Hazards

    Tubers of wild plants are highly acrid and can irritate the mouth and throat on ingestion due to the presence of calcium oxalate crystals.

    [CATE]
    Use
    Tubers reaching 10 kg are consumed after cooking. This taxon is extensively cultivated as a tuber crop, serving as an important food for humans and as animal feed.
    [FTEA]
    Use
    Is cultivated in many parts of the Old World Tropics for its massive starchy tuber.
    [KSP]
    Use
    Food, fodder, medicine.

    Images

    Distribution

    Native to:

    Andaman Is., Assam, Bangladesh, Borneo, Cambodia, China South-Central, China Southeast, East Himalaya, Hainan, India, Jawa, Laos, Lesser Sunda Is., Malaya, Maluku, Myanmar, New Guinea, Northern Territory, Philippines, Sri Lanka, Sulawesi, Sumatera, Taiwan, Thailand, Vietnam

    Introduced into:

    Cook Is., Fiji, Madagascar, New Caledonia, Niue, Samoa, Seychelles, Society Is., Trinidad-Tobago

    Common Names

    English
    Elephant yam

    Amorphophallus paeoniifolius (Dennst.) Nicolson appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Sep 4, 2006 s.coll. [s.n.], Indonesia K000455097
    Jun 1, 2000 s.coll. [s.n.], Indonesia K000455095
    Jun 1, 2000 s.coll. [s.n.], Indonesia K000455098
    May 1, 2000 Horsfield, T. [s.n.], Indonesia K000455096
    May 1, 2000 s.coll. [s.n.], Indonesia K000455094
    Jul 14, 1995 Collins, D.J. [1069], Thailand K000455106
    Jul 14, 1995 Collins, D.J. [1557], Thailand K000455107
    Jul 14, 1995 Kerr, A.F.G. [12624], Thailand K000455105
    Jan 1, 1994 Kerr, A.F.G. [12824], Thailand K000291508 Unknown type material
    Jan 1, 1994 Kerr, A.F.G. [12824], Thailand K000291509 Unknown type material
    Jan 1, 1994 Harley [136], Thailand K000291538 Unknown type material
    Jan 1, 1994 Harley [136], Thailand K000291537 Unknown type material
    Jan 1, 1994 Wichian [322], Thailand K000455108
    Jan 1, 1994 Kerr, A.F.G. [3619], Thailand K000455103
    Jan 1, 1994 Kerr, A.F.G. [3619], Thailand K000455104
    Jan 1, 1994 s.coll. [s.n.], Thailand K000291534 Unknown type material
    Jan 1, 1994 s.coll. [s.n.], Thailand K000291533 Unknown type material
    Jan 1, 1994 s.coll. [s.n.], Thailand K000291536 Unknown type material
    Jan 1, 1994 s.coll. [s.n.], Thailand K000291535 Unknown type material
    Jan 1, 1994 s.coll. [s.n.], Thailand K000291540 Unknown type material
    Jan 1, 1994 s.coll. [s.n.], Indonesia K000455099
    Jan 1, 1994 s.coll. [s.n.], Thailand K000455100
    Jan 1, 1994 s.coll. [s.n.], Thailand K000455101
    Jan 1, 1994 s.coll. [4722], Thailand K000455102
    Jan 1, 1994 s.coll. [2067], Vietnam K000455109
    Jan 1, 1994 s.coll. [s.n.], Andaman Is. K000950261 isolectotype
    Jan 1, 1994 s.coll. [s.n.], Andaman Is. K000950262 isolectotype
    Thailand 25032.000
    Thailand 29047.373
    Sri Lanka 29047.457
    Sri Lanka 29047.464
    Thailand 29047.621
    Thailand 29047.789
    Thailand 29047.795
    India 48116.000
    Bogner, J., Seychelles 34673.000
    Harley [136], Thailand K000291539 Unknown type material
    Prain, D. [s.n.], Andaman Is. K000950260 Unknown type material
    s.coll. [s.n.], Andaman Is. K000950257 Unknown type material
    s.coll. [s.n.], Andaman Is. K000950258 Unknown type material
    s.coll. [s.n.], Andaman Is. K000950259 Unknown type material

    First published in Taxon 26: 337 (1977)

    Accepted by

    • Baksh-Comeau, Y., Maharaj, S.S., Adams, C.D., Harris, S.A., Filer, D.L. & Hawthorne, W.D. (2016). An annotated checklist of the vascular plants of Trinidad and Tobago with analysis of vegetation types and botanical 'hotspots' Phytotaxa 250: 1-431.
    • Sykes, W.R. (2016). Flora of the Cook Islands: 1-973. National Tropical Botanical Garden, Hawaii.
    • Boyce, P.C., Sookchaloem, D., Hetterscheid, W.L.A., Gusman, G., Jacobsen, N., Idei, T. & Nguyen, V.D. (2012). Flora of Thailand 11(2): 101-325. The Forest Herbarium, National Park, Wildlife and Plant Conservation Department, Bangkok.
    • Mansor, M., Boyce, P.C., Othman, A.S. & Sulaiman, B. (2012). The Araceae of peninsular Malaysia: 1-146. Penerbit Universiti Sains Malaysia.
    • Kurniawan, A., Adjie, B. & Boyce, P.C. (2011). Studies on the Araceae of Sulawesi I: New taxa of Schismatoglottis and Homalomena, and a preliminary checklist and keys for Sulawesi Acta Phytotaxonomica et Geobotanica 61: 40-50.
    • Wu, Z. & Raven, P.H. (eds.) (2010). Flora of China 23: 1-515. Missouri Botanical Garden Press, St. Louis.
    • Yuzammi (2009). The genus Amorphophallus Blume ex Decaisne (Araceae - Thomsonieae) in Java Reinwardtia 13: 1-12.
    • Govaerts, R. & Frodin, D.G. (2002). World Checklist and Bibliography of Araceae (and Acoraceae): 1-560. The Board of Trustees of the Royal Botanic Gardens, Kew.
    • Welsh, S.L. (1998). Flora Societensis: 1-420. E.P.S. Inc. Utah.
    • Govaerts, R. (1995). World Checklist of Seed Plants 1(1, 2): 1-483, 1-529. MIM, Deurne.

    Literature

    Kew Species Profiles
    • Li, H. & Hetterscheid, W. (2013). Flora of China, Amorphophallus paeoniifolius.
    • Boyce, P. C. et al. (2012). Flora of Thailand, Volume 11, Part 2, Araceae. The Forest Herbarium, Bangkok, Thailand.
    • Das, S. S., Sen, M. Dey, Y. N., De, S. & Ghosh, A. K. (2009). Effects of petroleum ether extract of Amorphophallus paeoniifolius tuber on central nervous system in mice. Indian Journal of Pharmaceutical Sciences 71: 651–655.
    • Mabberley, D. J. (2008). Mabberley’s Plant-book: a Portable Dictionary of Plants, their Classification and Uses. 3rd Edition. Cambridge University Press, Cambridge, UK.
    • Roberts, T. (2002). Amorphophallus paeoniifolius. Australian National Botanic Gardens: Growing Native Plants.
    • Huxley, A., Griffiths, M. & Levy, M. (eds) (1999). The New Royal Horticultural Society Dictionary of Gardening. Volume 1 (A to C). Macmillan Reference, London.
    • Flach, M. & Rumawas, F. (eds) (1996). Plant Resources of South-East Asia, No. 9, Plants Yielding Non-Seed Carbohydrates. Backhuys Publishers, Leiden.
    Kew Backbone Distributions
    • Baksh-Comeau, Y., Maharaj, S.S., Adams, C.D., Harris, S.A., Filer, D.L. & Hawthorne, W.D. (2016). An annotated checklist of the vascular plants of Trinidad and Tobago with analysis of vegetation types and botanical 'hotspots' Phytotaxa 250: 1-431.
    • Sykes, W.R. (2016). Flora of the Cook Islands: 1-973. National Tropical Botanical Garden, Hawaii.
    • Boyce, P.C., Sookchaloem, D., Hetterscheid, W.L.A., Gusman, G., Jacobsen, N., Idei, T. & Nguyen, V.D. (2012). Flora of Thailand 11(2): 101-325. The Forest Herbarium, National Park, Wildlife and Plant Conservation Department, Bangkok.
    • Choudhary, R.K., Srivastava, R.C., Das, A.K. & Lee, J. (2012). Floristic diversity assessment and vegetation analysis of Upper Siang district of eastern Himalaya in North East India Korean Journal of Plant Taxonomy 42: 222-246.
    • Wu, Z. & Raven, P.H. (eds.) (2010). Flora of China 23: 1-515. Missouri Botanical Garden Press, St. Louis.
    • Ara, H. (2001). An Annotated Checklist of Aroids of Bangladesh Bangladesh Journal of Plant Taxonomy 8(2): 19-34.
    • Dy Phon, P. (2000). Dictionnaire des plantes utilisées au Cambodge: 1-915. Chez l'auteur, Phnom Penh, Cambodia.
    • Welsh, S.L. (1998). Flora Societensis: 1-420. E.P.S. Inc. Utah.
    • MacKee, H.S. (1994). Catalogue des plantes introduites et cultivées en Nouvelle-Calédonie, ed. 2: 1-164. Museum national d'histoire naturelle, Paris.
    • Sykes, W.R. (1970). Contributions to the flora of Niue Bulletin, New Zealand Department of Scientific and Industrial Research 200: 1-321.

    Sources

    Art and Illustrations in Digifolia
    Digital Image © Board of Trustees, RBG Kew

    CATE Araceae
    Haigh, A., Clark, B., Reynolds, L., Mayo, S.J., Croat, T.B., Lay, L., Boyce, P.C., Mora, M., Bogner, J., Sellaro, M., Wong, S.Y., Kostelac, C., Grayum, M.H., Keating, R.C., Ruckert, G., Naylor, M.F. and Hay, A., CATE Araceae, 17 Dec 2011.
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Flora of Tropical East Africa
    Flora of Tropical East Africa
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Herbarium Catalogue Specimens
    'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Species Profiles
    Kew Species Profiles
    http://creativecommons.org/licenses/by-nc-sa/3.0