Giant Taro, Giant Elephant Ear
Alocasia macrorrhizos

Family: Araceae

What it is like

Alocasia macrorrhizos is a PERENNIAL growing to 3 m (9ft) by 3 m (9ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10. The flowers are pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist soil. The plant is not wind tolerant.

Height (m): 3

Where it is found

Common along river banks and other damp places from sea-level to 500 metres.

E. Asia - Indian subcontinent, Malaysia.

Conservation Status: This taxon has not yet been assessed

Countries/locations it is found in

Africa, Asia, Australia, Bangladesh, Cambodia. Central America, Chuuk, Cook Islands, Cuba, Dominican Republic, East Timor, Fiji, French Polynesia, FSM, Guam, Guianas, Haiti, Hawaii, India, Indochina, Indonesia, Jamaica, Japan, Kiribati, Kosrae, Laos, Malaysia, Maldives, Marianas, Marquesas, Marshall Islands, Micronesia, Myanmar, Nauru, Northeastern India, North America, Pacific, Pakistan, Palau, Papua New Guinea, Philippines, Pohnpei, Puerto Rico, Rotuma, Samoa, Sao Tome and Principe, SE Asia, Singapore, Solomon Islands, South America, Sri Lanka, Suriname, Tahiti, Taiwan, Thailand, Timor-Leste, Tokelau, Tonga, Truk, Tuvalu, USA, Vanuatu, Vietnam, West Africa, West Indies, Yap

How it is used

Food

Rating: 3

Corm - cooked. The corm needs to be thoroughly cooked before being eaten in order to destroy the calcium oxalate crystals. Stems - cooked. The basal part of the stem, which can be up to 1 metre tall and 20cm in diameter, is peeled and used as a cooked vegetable. It can be added to soups and stews. A very easily digested starch can be obtained from the stem. The leaves and stalks of some cultivars are edible.

Root: includes bulbs, corms, tubers, rhizomes etc.

Stem: this often intergrades into leaves.

Medicine

Rating: 2

Giant taro is often used in traditional medicine in regions where the plant is cultivated as a food crop. All parts of the plant are used. The sap of the stem is used to treat earache or boils in the ear. Applied externally, it is used to treat cuts. In New Guinea, headaches are treated with the sap and the leaves. The leaves are said to be antimicrobial, antifungal, antioxidant, hepatoprotective, antidiarrheal, and antiprotozoal. The leaves and the rhizome are used in the treatment of impetigo, furunculosis, phlegmon and snake·bite in the form of a liquid extract for administration by mouth, and their residue is used for poulticing. They are also used in treating colic and vomiting, in a daily dose of 10 to 20g of dried rhizome in the form of a decoction. The rhizome is used to make a plaster that is applied topically and is said to be effective against furunculosis. Sexual insufficiency is treated by eating the leaves cooked in coconut milk. The roots are used to treat swollen lymph glands. The wood is used to treat stomach-ache and diarrhoea. The leaves and rhizomes are collected throughout the year. The leaves are used fresh. The rhizomes are boiled hard to reduce itching compounds, then sun·dried or heat·dried.

Antidiarrhoeal: Provides symptomatic relief for diarrhoea. Also see Astringent.

Antifungal: An agent that inhibits or destroys fungi. Used in the treatment of various fungal problems such as candida.

Antiinflammatory: Reduces inflammation of joints, injuries etc.

Hepatic: Acts on the liver (for better or worse!).

Skin: Plants used in miscellaneous treatments for the skin.

Other

Rating: 2

Agroforestry Uses: The plant grows rapidly in wetland conditions and has a propensity to accumulate metal contaminants such as zinc. It shows promise for use in sewerage treatment beds. Other Uses: A fibre is said to be obtained from the plant.

Fibre: Used for making cloth, rope, paper etc.

Fodder: Food given to the animals (including plants cut and carried to them) rather than forage for themselves.

Pollution: Plants used to combat pollution.

Soil reclamation: Plants that can be grown in such circumstances an the spoil tips of mines in order to restore fertility.

Fodder: Bank: Fodder banks are plantings of high-quality fodder species. Their goal is to maintain healthy productive animals. They can be utilized all year, but are designed to bridge the forage scarcity of annual dry seasons. Fodder bank plants are usually trees or shrubs, and often legumes. The relatively deep roots of these woody perennials allow them to reach soil nutrients and moisture not available to grasses and herbaceous plants.

Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.

Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.

Fodder: Bank: Fodder banks are plantings of high-quality fodder species. Their goal is to maintain healthy productive animals. They can be utilized all year, but are designed to bridge the forage scarcity of annual dry seasons. Fodder bank plants are usually trees or shrubs, and often legumes. The relatively deep roots of these woody perennials allow them to reach soil nutrients and moisture not available to grasses and herbaceous plants.

Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.

Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.

Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

A plant of the higher-rainfall areas of the lowland tropics, where it is cultivated at elevations up to 1,000 metres. It grows best in areas where annual daytime temperatures are within the range 20 - 25c, but can tolerate 10 - 32c.It prefers a mean annual rainfall in the range 2,500 - 3,500mm, but tolerates 2,000 - 4,200mm. Grows best in a position in some shade. Prefers a well-drained, humus-rich, fertile loam, though it is tolerant of a wide range of soil types. Dislikes water-logged soils. Prefers a pH in the range 5.7 - 6.3, tolerating 5 - 7.3. Grows best in higher-rainfall areas of the lowland tropics. Plants take from 400 - 600 days to mature, but the stems can then remain in a suitable condition for a considerable time. Whilst many forms of this plant contain calcium oxalate crystals (see notes above on toxicity), cultivars have been developed in India that do not contain oxalates. Like many species in the family Araceae, this plant has the ability to heat the flowering spadix as the pollen becomes ready for fertilization. This heat greatly increases the strength of the aroma released by the plant, thus attracting more pollinating insects. It can also have the effect of making the insects more active, thus increasing the level of fertilization. Position in the garden: Border, Pots/Tubs, Shrubbery. They do well in pots or tubs but may only reach one to one and a half metres in height.

Propagating it: Seed - best sown as soon as it is ripe. Germinates best at 24c. Division of the rootstock as the plant is coming into growth. Off-sets will appear at the base as it matures which can be easily transplanted.

Best place to grow:

Habit: Perennial

Hardiness: 10-12

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: Full shade, semi-shade, no shade

Moisture: Moist

Things to keep in mind

All parts of the plant contain calcium oxalate crystals. This substance is toxic fresh and, if eaten, makes the mouth, tongue and throat feel as if hundreds of small needles are digging in to them. However, calcium oxalate is easily broken down either by thoroughly cooking the plant or by fully drying it and, in either of these states, it is safe to eat the plant. People with a tendency to rheumatism, arthritis, gout, kidney stones and hyperacidity should take especial caution if including this plant in their diet.

Its other names

Local names

Abis, Alu, Ape, 'Apea mamala, Babai, Biga, Birah negeri, Birah, Bisech, Boafuredhdhe, Chara kanda, Conjevoi, Daun keladi, Desa-ala, Elephant Ear, Fale, Fine, Gabi, Habarala, Hai yu, Ka, Kadard, Kape, Kebei, Kiri ala, Kiri habarala, Kradat daeng, Lai, Maanaka, Mahuya-pein, Man kachu, Manaka, Mana saru, Mana thaso, Mankachu, Mankanda, Marambu, Merukankilangu, Oht, Onak, Pai, Papao-alaka, Papao-atolong, Parum sembu, Pein-gyi, Piga, Rata-ala, Sankhasaru, Sente, Spoon Lily, Ta'amu, Te kabe, Thagong, Via, Via dalo, Via mila, Wot.

Synonyms

Alocasia cordifolia (Bory) Cordem. Alocasia gigas Chantrier ex Andre Alocasia grandis N.E.Br. Alocasia indica (Lour.) Spach. Alocasia marginata N.E.Br. Alocasia metallica Schott Alocasia montana (Roxb.) Schott Alocasia pallida K.Koch & C.D.Bouche Alocasia plumbea Van Houtte Alocasia rapiformis (Roxb.) Schott Alocasia uhinkii Engl. & K.Krause Alocasia variegata K.Koch & C.D.Bouche Arum cordifolium Bory Arum indicum Lour. Arum macrorhizum L. Arum montanum Roxb. Arum mucronatum Lam. Arum peregrinum L. Arum rapiforme Roxb. Caladium indicum K.Koch Caladium macrorrhizon (L.) R.Br. Caladium metallicum Engl. Caladium odoratum Lodd. Caladium plumbeum K.Koch Calla badian Blanco Calla maxima Blanco Calocasia indica (Lour.) Kunth Colocasia boryi Kunth Colocasia macrorrhizos (L.) Schott Colocasia montana (Roxb.) Kunth Colocasia mucronata (Lam.) Kunth Colocasia peregrina (L.) Raf. Colocasia rapiformis (Roxb.) Kunth Philodendron peregrinum (L.) Kunth Philodendron punctatum Kunth