Alocasia (PROSEA Carbohydrates)

Plant Resources of South-East Asia Introduction

List of species

Alocasia (Schott) G. Don

Family: Araceae

Major species and synonyms

• Alocasia cucullata (Loureiro) G. Don, synonyms: Arum cucullatum Loureiro, Colocasia cucullata (Loureiro) Schott.

• Alocasia macrorrhizos (L.) G. Don, synonyms: Arum macrorrhizon L., Arum indicum Loureiro, Alocasia indica (Loureiro) Spach. (often wrongly referred to as Alocasia macrorrhiza (L). Schott).

• Alocasia portei Schott, synonym: Schizocasia portei Schott ex Engler.

Vernacular names

• General: Elephant's-ear plant (En).

• A. cucullata : Chinese taro (En)
• Malaysia: bira
• Thailand: wan-thorahot, wan-nokkhum, nangkwak
• Vietnam: ráy.

• A. macrorrhizos : Giant taro, giant alocasia, elephant ear (En). Grande tayove (Fr)
• Indonesia: bira (general), sente (Javanese), mael (Timor)
• Malaysia: birah negeri, keladi sebaring
• Papua New Guinea: abir, pia, via
• Philippines: biga, bira, badiang. Burma (Myanmar): pein-mohawaya
• Cambodia: k'da:t haôra:
• Laos: kaph'uk
• Thailand: kradatdam, hora
• Vietnam: khoai sáp, ráy, ráyăn.

• A. portei : Philippines: badiang.

Distribution

Alocasia contains about 60 species from tropical Asia, Australia and Oceania, often with subtropical extensions. Now cosmopolitan by introduction in ornamental horticulture, often naturalized in wet tropical areas. A. cucullata originates from China and possibly also from Indo-China. It is also cultivated (sometimes escaping) in India, Sri Lanka, Burma (Myanmar), Thailand and Peninsular Malaysia. A. macrorrhizos may have originated from Peninsular Malaysia, but has been introduced and often naturalized in the Malesian region and Oceania. A. portei is endemic to the Philippines (Luzon) and is occasionally cultivated elsewhere, e.g. in Peninsular Malaysia.

Uses

The corms, cormels, stems and leaves are used as food, vegetable and forage, mainly in subsistence agriculture in South and South-East Asia and Oceania, but only A. macrorrhizos is really important and most widely used. It is a source of very white, easily digested starch or flour; boiled stems are used medicinally as a laxative; chopped-up roots and leaves act as a rubefacient; juice from the petiole is used against coughs. A. portei is only occasionally used for food in the Philippines. Most species are also important as ornamentals.

Observations

Usually fleshy, large erect herbs, with thick starch-filled stems, with rhythmic or continuous growth and acrid, clear to milky sap; stems usually bearing short, slender, sometimes branched stolons or rhizomes terminating in small cormels. Leaves usually large with sheathing petiole and cordate-sagittate to hastate, sometimes peltate blades that are entire or deeply pinnatifid; venation usually conspicuous below. Inflorescence a spadix, usually paired; spathe tube-like at base with a lanceolate to oblong limb at the top; spadix monoecious, protogynous, finger-like, with female-flowered basal zone in the tube, sterile middle zone, male-flowered upper zone and ending with a conspicuous sterile appendix. Fruit a red to orange berry, several-seeded.

• A. cucullata : rhizome branched, tuberous; stem up to 50 cm long and 5 cm in diameter; leaves shortly peltate, shallowly cordate with very short basal lobes, up to 30 cm × 30 cm; petiole up to 75 cm long. Occurs in the lowlands, usually in open, wet locations.

• A. macrorrhizos : cormels rather large; stem 2-5 m tall, up to 30 cm in diameter; leaves sagittate, bluntly triangular in outline with strongly developed basal lobes, 25-75(-125) cm × 18-50(-75) cm; petiole up to 1.5 m long. Mainly known from cultivation, up to 1300 m altitude. Several forms and cultivars are known, varying mainly in leaf colour and size.

• A. portei : stem up to 60 cm tall and 12 cm in diameter; leaves ovate-sagittate, up to 2 m long, deeply pinnatifid with about 16 linear-lanceolate pinnae, dark metallic green; petiole up to 2 m long, marbled red-purple. Occurs in old clearings at medium altitude.

Propagation is possible by cormels or parts of cormels, and by seed if available. The crop usually needs 1-1.5 year. Long periods of drought or waterlogging are not tolerated. In many species all parts contain calcium oxalate crystals which can be removed by repeated cooking.

Selected sources

3, 5, 7, 9, 13, 14, 15, 19, 20, 25, 29, 32, 40, 43, 49, 51, 55, 58, 60, 69, 79, 81.

Authors

L.E. Groen, J.S. Siemonsma & P.C.M. Jansen