What kind of plant is the Giant Taro (Alocasia macrorrhizos)?
The Giant Taro (Alocasia macrorrhizos) is a large evergreen herbaceous plant of the genus Alocasia in the family Araceae, native to South America, and a common ornamental plant in tropical and subtropical regions. It is commonly known as hen yutou, langdu, wild taro, mountain taro, big-root taro, big-worm taro, tianyu, tianmeng, and so on. When grown as an ornamental plant it is called "Drip Guanyin" (Dripping Guanyin). Under conditions of warm, humid air and sufficient soil moisture, water drips down from the leaf tips or leaf edges, and its flowers resemble Guanyin, hence the name Drip Guanyin.
The Giant Taro (Alocasia macrorrhizos) has creeping rhizomes and erect aboveground stems, with adventitious buds sprouting from the base. The leaves are numerous, with green or dirty-purple petioles arranged in a spiral. The petioles and midribs turn black, brown or white. The inflorescence stalks, 2 to 3 in number, grow in clusters, cylindrical, usually green, sometimes dirty purple. The spathe tube is green, ovate or short-elliptic. The spadix is fragrant, with the female inflorescence white, the sterile male inflorescence greenish-white, and the fertile male inflorescence pale yellow. The berries are red, ovoid. It flowers in all seasons, but often does not flower under dense shade in the forest.
The Giant Taro (Alocasia macrorrhizos) grows at temperatures of 20 to 30°C, and can tolerate low temperatures down to 8°C. In summer, as long as the soil is kept moist, water is sprayed frequently and shade is provided, it can still grow normally during high temperatures; in winter, room temperature must not fall below 5°C. As an understory plant of tropical rainforests, it requires high humidity to grow and does best in diffused light. It is a shade-tolerant plant that prefers a semi-shaded environment, and should be placed in a spot that is both shaded and well ventilated.
The Giant Taro (Alocasia macrorrhizos) is found in the tropical and subtropical regions of Jiangxi, Fujian, Taiwan, China, Hunan, Guangdong, Guangxi, Sichuan, Guizhou, Yunnan and other places, below 1700 m in altitude, often growing in large patches at the edges of tropical rainforests or under wild banana groves in river valleys. Abroad, it is also cultivated from Bangladesh and northeastern India to the Malay Peninsula, Indochina, as well as the Philippines and Indonesia.
The rhizome of the Giant Taro (Alocasia macrorrhizos) is used medicinally and is highly effective for abdominal pain, cholera, hernia and the like. It can also treat pulmonary tuberculosis, rheumatic arthritis, bronchitis, influenza, typhoid and rheumatic heart disease. Externally it is used to treat sores and swellings, snake and insect bites, and burns. Mixed with kerosene for external use, it treats neurodermatitis. It is toxic: after the sap of the fresh plant touches the skin it causes itching, and if it gets into the eyes it can cause blindness. If the stem or leaves are eaten by mistake, the throat and tongue itch, swell, and salivation occurs, along with burning pain in the stomach and intestines, nausea, diarrhea and convulsions; in severe cases, suffocation and death from cardiac paralysis occur. In folk medicine, a little ginger juice is boiled with vinegar and taken orally or used as a gargle to counteract the poison. The rhizome is rich in starch and can be used as an industrial substitute, but it must not be eaten.