Giant Taro, Giant Elephant Ear

Alocasia macrorrhizos

Physical Characteristics

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.

Distribution

E. Asia - Indian subcontinent, Malaysia.

Habitats

Edible Uses

Edible Parts: Leaves Root Stem Edible Uses: Corm - cooked[300 ]. The corm needs to be thoroughly cooked before being eaten in order to destroy the calcium oxalate crystals[300 , 418 ]. Stems - cooked[300 ]. 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[300 , 418 ]. It can be added to soups and stews[418 ]. A very easily digested starch can be obtained from the stem[300 , 418 ]. The leaves and stalks of some cultivars are edible[418 ].

Medicinal Uses

Antidiarrhoeal Antifungal Antiinflammatory Hepatic Skin 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[283 , 311 ]. The sap of the stem is used to treat earache or boils in the ear[311 ]. Applied externally, it is used to treat cuts[311 ]. In New Guinea, headaches are treated with the sap and the leaves[311 ]. 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[283 ]. The rhizome is used to make a plaster that is applied topically and is said to be effective against furunculosis[283 ]. Sexual insufficiency is treated by eating the leaves cooked in coconut milk[311 ]. The roots are used to treat swollen lymph glands[311 ]. The wood is used to treat stomach-ache and diarrhoea[311 ]. 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[283 ].

Known Hazards

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[238 ].